Expression of heterologous polypeptides in halobacteria

ABSTRACT

This invention relates to the preparation and use of expression systems capable of producing heterologous polypeptides in halobacterial hosts.

The Government has rights in this invention pursuant to Grant No. GM-31785 awarded by the National Institutes of Health.

REFERENCE TO RELATED APPLICATIONS

This is a continuation of application Ser. No. 08/313,553 filed on Sep. 27, 1994, now U.S. Pat. No. 5,641,650, which is a continuation of application Ser. No. 08/038,662 filed Mar. 25, 1993, now abandoned.

FIELD OF THE INVENTION

The present invention is directed to the preparation and use of a halobacterial expression system that is capable of producing soluble and transmembrane heterologous polypeptides that are not endogenous to said halobacterium.

BACKGROUND OF THE INVENTION

Halobacteria are found in nature in evaporating salt water ponds under conditions of intense light and low oxygen saturation. They contain distinctive brightly colored pigments such as the orange-red pigment, bacterioruberin, or patches of "purple membrane". Halobacteria belong to a phylogenetically distinct group of prokaryotic organisms--the "archaebacteria" (Arcbaea)--that are as distantly related to the eubacteria as they are to the eukaryotes.

Archaebacteria possess some attributes in common with the eukaryotes and the eubacteria, as well as characteristics that are uniquely archaeal. For example, the archaebacteria possess a eukaryotic-like transcription apparatus with a 7-12 subunit RNA polymerase which is immunologically related to eukaryotic RNA polymerase (1) and promoter structures are similar to those of RNA Pol II (2). In contrast, the archaebacteria have prokaryotic cellular morphology and 23S, 16S and 5S rRNAs with the genes encoding the rRNAs arranged into eubacterial-like operons (3). Notably, the archaebacteria are unique in their membrane composition.

Bacteriorhodopsin (BR) is found as the sole protein in specialized crystalline patches of the "purple membrane" in halobacteria. Synthesis of BR is induced by high light intensity and low oxygen tension and the patches of purple membrane can constitute up to 50% of the archaebacterium Halobacterium halobium cell surface area.

BR consists of a complex of one protein (bacterio-opsin) along with the chromophore retinal in a 1:1 stoichiometric ratio (4). This complex is embedded in the lipid matrix as seven transmembrane hydrophobic α-helices in a trimeric configuration (5). Retinal is covalently attached at lysine at position 216 approximately one-third of the way across the transmembraneous region of one of the α-helices (6). The complex of bacterio-opsin with retinal was named bacteriorhodopsin (BR). The so-called bop gene encodes the light-driven protein pump bacteriorhodopsin (BR) in H. halobium.

There has been some reported research on expression of endogenous polypeptides in halobacteria (7, 8 and 9).

SUMMARY OF THE INVENTION

The present invention is directed to the preparation and use of an expression system for heterologous polypeptide production in a halobacterial host.

In a first aspect, such systems in their broadest context would include transcription and translation regulatory DNA, DNA encoding a heterologous polypeptide that is not endogenous to the halobacterial host and DNA encoding transcription and translation stop signals.

Preferably such systems would include DNA encoding the pre-sequence of bacteriorhodopsin such that the polypeptide which is expressed is attached to the pre-sequence, thus allowing the heterologous polypeptide to be properly targeted to the membrane and either inserted into or secreted across the membrane.

Yet another preferred embodiment of the present invention uses the transcription and translation regulatory sequences and the translation and transcription stop sequences of the bacteriorhodopsin gene, either in the presence or absence of the bacteriorhodopsin pre-sequence. The use of the regulatory and stop sequences of the bacteriorhodopsin gene serves to allow high level expression of the heterologous polypeptide sequence.

In a second aspect, the present invention is also directed to utilizing the C-terminal domain of the bacteriorhodopsin polypeptide in order to enhance the separation of the mature heterologous polypeptide from the membrane of the halobacterial host following expression. In a preferred embodiment of this aspect, DNA encoding a unique protease site is introduced between said C-terminal sequence and the DNA encoding the heterologous polypeptide.

In a preferred embodiment of this aspect, high levels of expression of the heterologous polypeptide linked to the C-terminal region of bacteriorhodopsin are achieved by using DNA encoding the transcription and translation regulatory and stop sequences of the bacteriorhodopsin gene.

A further preferred embodiment of the invention is directed to the use of the bacteriorhodopsin pre-sequence to enhance expression of the heterologous polypeptide linked to the C-terminal region of bacteriorhodopsin.

The invention is directed to such systems in all their equivalent aspects, including expression vectors, halobacterial hosts transformed with such vectors and methods for producing, isolating and optionally further purifying heterologous polypeptides using such expression vectors.

DETAILED DESCRIPTION

The present invention has been described herein by disclosing the preferred embodiments and best mode. It will be understood, however, that having detailed the method first used by the present inventors to produce the heterologous polypeptide expression system in halobacterium, it will be apparent to those skilled in the art that one could make modifications within the general skill of the art to produce expression systems that differ in one or more ways from that originally described.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a restriction map of the PstI/BamHI fragment containing the bacteriorhodopsin gene and about 400 bp of upstream sequences from Halobacterium halobium strain R1.

FIG. 2 shows the nucleic acid sequence (SEQ ID NO:1) of the PstI/BamHI construct of FIG. 1 containing the bacteriorhodopsin gene and about 400 bp of upstream sequences from Halobacterium halobium strain R1. Also shown is the amino acid sequence (SEQ ID NO:2) of the BR protein translation product.

FIG. 3 shows the restriction map of pUBP2.

FIG. 4 is a map of the secondary structure of the mature BR protein (SEQ ID NO:3).

FIG. 5 is a restriction map of the PstI/BamHI fragment containing BR regulatory sequences and the gene for human muscarinic acetylcholine receptor (Type HM1) in pENDS-OM1.

FIG. 6 shows the nucleic acid sequence (SEQ ID NO:6) of the PstI/BamHI fragment of FIG. 5 containing the gene for human muscarinic acetylcholine receptor (Type HM1) of pENDS-OM1. Also shown is the amino acid sequence (SEQ ID NO:7) of HM1.

FIG. 7 is a restriction map of the PstI/BamHI fragment containing the BR regulatory sequences and gene for human muscarinic acetylcholine receptor (Type HM1) in pENDS-OM2.

FIG. 8 shows the nucleic acid sequence (SEQ ID NO:8) of the PstI/BamHI fragment of FIG. 7 containing the gene for human muscarinic acetylcholine receptor (Type HM1) which lacks the I3 domain. The amino acid sequence (SEQ ID NO:9) of HM1 having a deleted I3 domain is shown.

FIG. 9 is a restriction map of the PstI/BamHI fragment containing the BR regulatory sequences and the rat serotonin receptor (Type 1C) gene.

FIG. 10 shows the nucleic acid sequence (SEQ ID NO:10) of the PstI/BamHI construct of FIG. 9 containing the rat serotonin receptor gene and the amino acid sequence (SEQ ID NO:11) of the rat serotonin receptor.

FIG. 11 is a Southern blot of DNA isolated from H. halobium Bop deficient strain L33 transformed with pUBP2 containing the rat serotonin receptor (Type 1C) gene. Lanes 1-10, 12-19, 21-24 and 27 contained DNA from strain L33 transformed with pUBP2 containing the PstI/BamHI fragment of FIGS. 9 and 10 (SEQ ID NO:10). Lanes 11 and 25 are positive controls which contained purified plasmid DNA (i.e. pUBP2 containing serotonin receptor gene). Lane 29 contained DNA from strain L33. The arrow indicates the location of the PstI/BamHI fragment corresponding to serotonin DNA.

FIG. 12 shows a Northern blot of total RNA isolated from H. halobium Bop deficient strain L33 transformed with pUBP2 containing the rat serotonin receptor gene. Lanes 2 and 5 contain RNA from wild type strain L33 transformed with the 1.2 kb PstI/BamHI fragment containing the bop gene in pUBP2 as a control. Lanes 1, 3 and 4 contain DNA from L33 transformed with the rat serotonin receptor gene. The 1.85 kb PstI/BamHI fragment of FIGS. 9 and 10 was used as probe. The arrow shows the location of the rat serotonin receptor RNA.

FIG. 13 is a restriction map of the PstI/BamHI fragment containing BR regulatory sequences and the human thrombin receptor gene.

FIG. 14 shows the nucleic acid sequence (SEQ ID NO:12) of the PstI/BamHI fragment of FIG. 13 containing the human thrombin receptor gene and the amino acid sequence (SEQ ID NO:13) of the human thrombin receptor.

FIG. 15 shows the restriction maps of pβgbop, pEK17, pBATC, p1.2KbBop and pBRAT.

FIG. 16 shows a restriction map of the PstI/BamHI fragment containing BR regulatory sequences, the bacterio-opsin gene and the gene encoding the Escherichia coli catalytic subunit of aspartate transcarbamylase.

FIG. 17 shows the nucleic acid sequence (SEQ ID NO:14) of the PstI/BamHI fragment of FIG. 16 containing the bacterio-opsin and the E. coli aspartate transcarbamylase genes and the amino acid sequence (SEQ ID NO:15) of the BR/E. coi aspartate transcarbamylase fusion protein.

FIG. 18 shows a Western blot of H. halobium transformed with pBRAT. Blots were probed with antibodies to the catalytic subunit of aspartate transcarbamylase. Lane 2 contains E. coli aspartate transcarbamylase. Lanes 6-9 and 11 contain protein from H. halobium transformed with pBRAT. The arrow in lane 8 indicates the position of the bacteriorhodopsin/aspartate transcarbamylase (BR/ATCase) fusion protein.

FIG. 19 shows the localization of expression of the bacteriorhodopsin/aspartate transcarbamylase (BR/ATCase) fusion protein to the purple halobacterial cell membranes. Washed H. halobium whole cell membranes fractionated on sucrose density gradients (A) were electrophoresed on SDS-polyacrylamide gels and stained with Coomassie blue (B). Lanes in (B) contained the following protein samples: Molecular weight markers (lane 1); unfractionated total membranes from H. halobium strain L33 transformed with pBRAT (lane 2); purple membrane from H. halobium strain L33 transformed with a 1.2 Kb PstI/BamHI fragment containing the bop gene (lane 3) or with a 9 Kb genomic DNA fragment containing the bop gene (lane 4); total membranes from H. halobium strain L33 (lane 5); purple membrane from wild-type H. halobium strain R1 (lane 6); purple membrane of H. halobium strain L33 transformed with pBRAT (lanes 7-9).

DEFINITIONS

The term "expression vector" herein has a functional definition and includes vectors capable of expressing DNA sequences contained therein, where such sequences are operably linked to other sequences capable of effecting their expression. In the present specification, "vector" and "plasmid" are used interchangeably as the plasmid is the most commonly used form of vector. However, the invention is intended to include such other forms of expression vectors capable of equivalent functions and which are or become known in the art.

By the term "operable" herein, and grammatical equivalents, is meant that the respective DNA sequences are operational and work for their intended purposes.

The term "heterologous polypeptide" herein refers to presently known or unknown polypeptides not endogenous to the host cell, or if endogenous to the host cell, are obtainable herein in amounts not achievable in native state. Included within the definition are the halobacterial non-retinal binding proteins. Examples of heterologous polypeptides include, but are not restricted to, polypeptides from eukaryotes, eubacteria, archaebacteria, synthetic polypeptides and polypeptides containing bioequivalent amino acid analogs. Further included are other members of the 7-transmembrane crossing family such as muscarinic acetylcholine receptor, serotonin receptor, thrombin receptor, 6-adrenergic receptor, and the like. Heterologous polypeptides also include membrane proteins, for example, cystic fibrosis transmembrane conductance regulator, and soluble proteins, such as various enzymes (e.g. proteases and aspartate transcarbamylase). Each is used in accord with their known or determined function biologically and is adapted for such in accord with procedures generally known in the art.

By the term "DNA encoding heterologous polypeptide" is meant a DNA sequence coding for a polypeptide that is not endogenous to the host wherein it is expressed. Because of the high GC content (i.e. about 58-68%) of the genome of halobacteria, it is preferred that the DNA sequence encoding the heterologous polypeptide be in this range, although sequences with higher and lower GC content than that usually found in halobacteria can be used. For example, we have been successful in expressing Escherichia coli aspartate transcarbamylase, having a GC content of about 50%, as a fusion protein to the C-terminus of BR.

The term "transcription and translation regulatory DNA" and equivalents, in its broadest sense refers to a DNA sequence responsible for the dual transcription and translation elements of expression. In a preferred embodiment the regulatory DNA is that of the bacteriorhodopsin gene (from -364 to +41 relative to the RNA start site, FIG. 2 (SEQ ID NO:1)).

In an alternative embodiment, the regulatory DNA contains about 4000 bp of sequences (from about -4000 to +41) upstream of the bop gene and includes three other genes of the bop gene cluster, which include brp (13), bat (14) and blp (Gropp & Betlach, manuscript in preparation). Some or all of these genes may be regulatory genes.

By the term "transcription and translation stop signals" and equivalents, in its broadest scope is meant DNA which functions to terminate transcription and translation, respectively. It is preferred that the transcription and translation stop signals be those of the bacteriorhodopsin gene.

By the term "pre-sequence of bacteriorhodopsin gene" herein is meant a sequence of about 13 amino acids required to target bacteriorhodopsin to the membrane. The 13 amino acid pre-sequence is encoded by nucleotides +3 to +41 relative to the RNA start site depicted in FIG. 2 (SEQ ID NO:1).

By the term "halobacterium host" is meant strains belonging to Halobacterium including species of extreme and moderate halophiles having a wild-type genotype. Examples of the extreme halophilic species having a wild type genotype include Halobacterium saccharovorium (ATCC 29252), Halobacterium california (ATCC 38799), Halobacterium halobium (CCM 2090) and Halobacterium valismortis (ATCC 29-715). Wild type moderate halophiles are exemplified by the species Halobacterium mediterannei (ATCC 33500). It may be preferred that the halobacterial host species is bacteriorhodopsin deficient. Bacteriorhodopsin deficient species are either wild-type, such as H. volcanii, or mutants, such as L33 (15), S9F1x3 (16), IV-8 (17) and IV-14 (17). Bacteriorhodopsin deficient mutants derived from strains which express purple membrane constitutively, such as 133, or inducibly, are useful for different applications. Depending on the nature of the upstream regulatory regions in the expression vector construct, inducible strains permit regulated expression whereas constitutive strains do not.

The term "restriction site" herein refers to a DNA sequence recognizable by an endonuclease as a site of DNA cleavage.

By the term "C-terminal sequence", "C-terminal region" and equivalents, is meant the polypeptide sequence at the C-terminus of bacteriorhodopsin; See FIG. 4.

By the term "unique protease site" is meant an amino acid sequence recognizable by a protease as the site of cleavage of the polypeptide wherein it is disposed and which is absent from the heterologous polypeptide expression product. In a preferred embodiment, the protease site (Ile-Glu-Gly-Arg) (SEQ ID NO:4) of factor X_(a) is used in view of the rarity of this sequence.

EXAMPLES

1. Cloning the DNA sequence encoding the heterologous polypeptide into a halobacterial expression vector

i. Constructs for express ion of membrane proteins

All constructions are assembled using standard molecular techniques (12) including PCR. Expression vectors can be prepared in a variety of conventional ways. Although others may be used, a preferred halobacterial cloning vector to be adapted into an express ion vector is plasmid pUBP2 (FIG. 3) described by Blaseio et al. (7). The plasmid may be isolated using conventional techniques. For example, the plasmid may be purified using caesium chloride-ethidium bromide density gradients, electrophoresis from an agarose gel onto a dialysis membrane, use of commercially available chromatography columns for the separation of plasmids, such as magic minipreps DNA purification system (Promega Corp., Madison, Wis.), etc.

The expression vectors which will be employed will normally include a marker which allows for selection of cells into which the DNA has been integrated, as against cells which have not integrated the DNA construct. An example of commonly used selection markers is antibiotic resistance. Two markers are available for selection of halobacteria, including resistance to novobiocin (8) and mevinolin (7). It is preferred that the marker used be that for mevinolin resistance; mevinolin is a HMG CoA reductase inhibitor (7). This marker is present in the preferred cloning plasmid pUBP2 (FIG. 3).

To convenience insertion of DNA sequences, plasmids will contain polylinker sequences containing various restriction sites. Several examples of polylinkers are known and available (12). A typical polylinker is polylinker 1 (123) (FIG. 3) which contains restriction sites for HindIII, SphI MluI, XhoI PstI, SalI, XbaI, BamHI, HindIII, XbaI and KpnI. Another typical polylinker is polylinker 2 (3.70) (FIG. 3) with restriction sites for SphI, EcoR5, SstI, SmaI and EcoRI.

The DNA sequence encoding the heterologous polypeptide is inserted such that it is placed downstream from a transcription and translation regulatory region containing a promoter and a ribosome binding site using standard techniques. It is preferred that the promoter used is inducible, allowing controlled expression of the heterologous polypeptide product. In a preferred embodiment of the invention, the transcription and translation regulatory sequences of the bacteriorhodopsin gene will be used. The bacteriorhodopsin gene may be isolated from the genome of halobacteria using appropriate restriction enzymes. Transcription and translation regulatory sequences of the bacteriorhodopsin gene are located in the region of -365 to +41 relative to the RNA start site of the bacteriorhodopsin sequence depicted in FIG. 2 (SEQ ID NO:1).

To effect appropriate termination of heterologous polypeptide synthesis, DNA sequences encoding transcription and translation stop signals are placed downstream of the inserted DNA sequence encoding the heterologous polypeptide sequence using well known techniques (12). Preferably, the sequences downstream of the bacteriorhodopsin gene (FIG. 2) (SEQ ID NO:1) which includes the translational stop codon (TGA) followed by ˜80 bp which include the transcriptional termination signal are employed as stop signals.

Where it is advantageous to produce a heterologous transmembrane polypeptide which is targeted to the halobacterial membrane, DNA encoding the heterologous polypeptide is ligated downstream of DNA encoding the pre-sequence of BR.

The heterologous gene of interest may be cloned into the E. coli plasmid, pUC19 (20), along with BR regulatory sequences such that all cloned sequences will reside on a DNA fragment containing two unique restriction sites (choice of PstI, BamHI, SmaI). More specifically, the heterologous gene is ligated such that it is in frame with the BR pre-sequence, downstream of the bacteriorhodopsin regulatory sequences/promoter and upstream of the bacteriorhodopsin transcriptional and translational termination sequences. A specific unique protease site may be engineered into some constructions between the BR pre-sequence and the heterologous gene.

A 1.2 kbp fragment containing the bop gene and ˜370 bp of upstream sequences was isolated from H. halobium strain R1 DNA using PCR and cloned into the PstI/BamHI sites of pUC19 (denoted p1.2Kbbop) (FIG. 15B). Two endogenous AlwNI sites were removed from the cloned 1.2 kbp fragment: i) one site located 165 bp upstream of the bop gene start codon (SEQ ID NO:1) was removed by generating a G→T point mutation using the Kunkel method (29), and ii) the second AlwNI site located 7 bp upstream of the bop gene stop codon was removed using the Transformer Site-Directed Mutagenesis kit (Clontech Laboratories, Inc., Palo Alto, Calif.). Subsequently, a ˜400 bp PstI/AlwNI fragment (denoted "bop 5' fragment") containing the bop upstream sequences, DNA encoding the BR presequence and the first four (extrahelical) residues of BR was isolated by PCR from the mutated 1.2 kbp fragment. Concurrently, a ˜100 bp NotI/BamHI fragment (denoted "bop 3' fragment") containing DNA encoding six C-terminal residues of BR, the BR stop codon and the transcriptional termination sequences of BR (up to 44 bp downstream of the stop codon) was obtained from the 1.2 kbp bop gene fragment by preparative digestion and purification (Prep-A-Gene, BioRad, Richmond, Calif.). In addition, an endogenous AlwNI site located in pUC19 (position 1217) was removed using the Clontech Transformer kit and the mutated pUC19 was preparatively digested with PstI/BamHI and preparatively purified (denoted "vector fragment"). The three fragments (i.e., "bop 5' fragment", "bop 3' fragment" and "vector fragment") were ligated with DNA fragments containing various heterologous genes engineered to be in frame with the BR presequence and extrahelical residues and to contain a single AlwNI site at the 5' terminus of the fragment and a single NotI site at the 3' terminus of the fragment as described below. In all of the heterologous genes, endogenous AlwNI, NotI, BamHI and PstI sites were first removed (if necessary) to facilitate the construction. Once the heterologous gene was cloned along with the BR 5' and 3' regulatory sequences into pUC19, this intermediate construct (denoted "pENDs") was preparatively digested with PstI/BamHI

Subsequently, the PstI/BamHI restriction fragment containing the heterologous gene with the regulatory sequences of BR was preparatively isolated away from pUC19 sequences by agarose gel electrophoresis, purified using Prep-A-Gene (Bio-Rad, Richmond, Calif.) and cloned into the E. coli/H. halobium shuttle vector, pUBP2 (7). pUBP2 carries the pBR322 replicon and ampicillin resistance marker, the halobacterial plasmid pHH1 origin of replication and a mevinolin resistance marker. Mevinolin resistance is encoded by an up-promoter mutation of the HMG-CoA reductase gene.

The construction was verified by restriction mapping and nucleotide sequencing across the junctions between 5' and 3' BR regulatory sequences and the heterologous gene.

a. Human muscarinic acetylcholine receptor (Type HM1)

Two different constructs were made with this gene. The first (denoted pENDs-OM1) contained the entire gene whereas the second (denoted pENDs-OM2) lacked the large internal cytoplasmic loop (i.e., I3 ) which is thought to be involved in signaling. Prior to the generation of the constructions described below, two endogenous AlwNI sites and one endogenous PstI site were removed from human muscarinic acetylcholine receptor (denoted HM1) cloned in pGEM3 (Promega Corp, Madison, Wis.) using either the Clontech Transformer kit or the Kunkel method (29). The positions of the removed sites are shown in FIG. 6 (SEQ ID NO:6).

pENDs-OM1 was generated as follows. First, the HM1 gene was isolated by PCR from pGEM3/HM1 so as to contain an AlwNI site at the 5' terminus and a Not I site the 3' terminus of the PCR fragment. This PCR fragment was ligated to the "bop 5' fragment", "bop 3' fragment" and "vector fragment" described above and transformed into E. coli. The resultant plasmid was named pENDs-OM1. pENDs-OM1 contains the methionine start codon of HM1 located 4 codons downstream from the BR 5' sequences. Nine extra base pairs generated by introduction of the AlwNI site encode 3 extra residues (i.e., gln, ala, leu) located in frame between the BR 5' sequences and the start codon of the HM1 gene. At the 3' terminus of the gene, the HM1 stop codon precedes the BR stop codon by 48 bp. From pENDs-OM1, the BR regulatory sequences with the HM1 gene were transferred to pUBP2 on a PstI/BamHI fragment (FIG. 5 and FIG. 6, SEQ ID NO:6) as described above.

pENDs-OM2 was generated in a similar manner as its sibling construct. First, however, deletions of the I3 domain were introduced after digestion of the HM1 gene at the unique StuI restriction site (position 712 relative to the start codon of the HM1 gene, SEQ ID NO:6), followed by digestion with the exonuclease Bal-31 for varying times at 4° C. The blunt-ended product was self-ligated to yield mutants with deletions of varying size within the I3 domain. One of these was chosen for further study which lacked amino acid residues 231 through 357 of HM1 (SEQ ID NO:7). DNA from this mutant was used to generate a PCR fragment containing the HM1 gene (less I3 loop) with a 5' AlwNI site and a 3' Not I site. This PCR fragment was identical to the fragment described above except for the lack of the I3 loop and was used to generate pENDs-OM2 in a similar manner to the pENDs-OM1 construct. The sequence of the PstI/BamHI fragment containing the BR regulatory sequences and the HM1 gene (less I3 loop) is shown in FIG. 8 (SEQ ID NO:8).

b. Rat serotonin receptor (Type 1 C)

The rat serotonin receptor gene (denoted "Ser") cloned as a 3 Kb EcoRI cDNA fragment on the plasmid pSR1c (27) was used as a basis for the following constructions. The Ser gene contains no endogenous AlwNI, NotI, BamHI and PstI sites and was adapted for expression in H. halobium as follows. AlwNI and NotI cloning sites were introduced within the 5' coding and 3' noncoding regions of the Ser gene, respectively. In addition, DNA encoding a poly-aspartic acid peptide was placed in frame upstream of the Ser gene and downstream of the AlwNI site. Translation of this sequence generates a peptide epitope useful for subsequent detection of expressed protein (31). This fragment was isolated and ligated to the "bop 5' fragment", "bop 3' fragment", and "vector fragment" described above and transformed into E. coli. The resultant plasmid was named pENDs-Ser and contains the 36th codon of the rat serotonin receptor gene preceded by DNA encoding the peptide epitope and BR 5 ' sequences. Nine extra base pairs generated by the construction and encoding 3 extra residues (i.e., gln, ala, leu) are located in frame between the BR 5' sequences and the epitope sequences. At the 3' terminus of the gene, the Ser stop codon precedes the BR stop codon by 18 bp. Following the construction of pENDs-Ser, the BR regulatory sequences with the Ser gene were transferred to pUBP2 on a PstI/BamHI fragment (FIG. 9 and FIG. 10, SEQ ID NO:10).

c. Human thrombin receptor

A clone of the human thrombin receptor gene (denoted "Thromb") (33) was used as a basis for the following constructions. Four endogenous DNA restriction sites were removed from the gene using the Kunkel method (29). These included three AlwNI sites (291, 945, and 1038) and one PstI site (537). Positions are given relative to the first base of the start codon of the gene. "pENDs-Thromb" was generated as follows. An AlwNI/NotI fragment containing the gene was generated using oligonucleotide-directed-insertion-mutagenesis and PCR. Included on this fragment were additional nucleotide sequences encoding short peptides for use in the detection and purification of the expressed protein. The AlwNI/NotI fragment containing the gene along with epitope encoding sequences was ligated to the "bop 5' fragment", "bop 3' fragment" and "vector fragment" described above and transformed into E. coli. The resultant plasmid was named pENDs-Thromb. In pENDs-Thromb, thirty-three extra base pairs generated by the construction and encoding eleven extra amino acids are located in frame between the BR 5' sequences and the Thromb sequences. Twenty seven of the extra residues encode a poly-aspartic acid peptide sequence which when translated generates a peptide epitope useful for detection of expressed protein (31). At the 3' terminus of the gene, six histidine codons have been inserted upstream of the Thromb stop codon. These histidine codons are intended to aid in the affinity purification of expressed protein (26). At the 3' terminus of the gene, the Thromb stop codon precedes the BR stop codon by 18 bp.

The BR regulatory sequences with the human thrombin receptor gene may be transferred into pUBP2 on a PstI/BamHI fragment (FIG. 13 and FIG. 14, SEQ ID NO:12) as described above.

ii. Constructs for expression of soluble proteins

Where it is desired that heterologous soluble polypeptide be released extracellularly into the culture medium following expression, the DNA sequence encoding the heterologous polypeptide may be ligated to DNA encoding the pre-sequence of bacteriorhodopsin (FIG. 2 (SEQ ID NO:1), from +3 to +41 relative to the RNA start site) using techniques well known to those skilled in the art (12).

Where it is advantageous to produce a heterologous soluble polypeptide that is targeted, following expression, to the halobacterial membrane, DNA encoding the heterologous polypeptide is ligated downstream of the DNA encoding the C-terminal region (FIG. 2 and FIG. 4 (SEQ ID NOs:1 and 3)) of bacteriorhodopsin or to fragments thereof.

To facilitate subsequent purification of the heterologous polypeptide product, a DNA sequence encoding a unique protease site is engineered between DNA encoding the bacteriorhodopsin C-terminal region and DNA encoding the heterologous polypeptide. Sequences encoding unique protease cleavage sites are known and include, for example, subtilisin, thrombin, enterolinase, and factor X_(a). In a preferred embodiment, a DNA sequence encoding the amino acid sequence Ile-Glu-Gly-Arg (SEQ ID NO:4) is used to encode a unique protease site which is recognized by Factor X_(a).

Design of the soluble protein expression vector and methods used are similar to that described above for membrane proteins. However, soluble proteins are expressed as in-frame fusions to the C-terminal region of BR. Thus, these fusion proteins will have membranous domain (i.e. BR or portions thereof) and a soluble domain (i.e. heterologous polypeptide). The heterologous gene is cloned at the C-terminus of BR, between the bacteriorhodopsin gene and the downstream transcriptional/translational termination sequences of BR. In addition, a unique protease site is engineered between BR and the heterologous gene to facilitate subsequent purification of the protein. The final construct is cloned into the E. coli/H. halobium shuttle vector, pUBP2 (7).

a. E coli Aspartate Transcarbamylase (catalytic subunit)

The catalytic subunit of Aspartate Transcarbamylase, (denoted ATCase), a soluble protein, has been fused to the C-terminus of BR as follows. The bop gene containing plasmid, pβgbop (32), was digested at the unique NotI site located near the 3 ' terminus of the bop gene (see FIG. 15A). Subsequently, this NotI site was filled-in to create a blunt site (12). The resulting DNA was digested with SphI to generate two fragments, a large fragment (denoted fragment 1) containing the vector along with the N-terminus of the bop gene and a small fragment containing internal bop gene sequences. Fragment 1 was isolated and purified. A second aliquot of pβgbop was digested with SphI/HaeII and a 217 bp fragment (denoted fragment 2) containing an internal portion of the bop gene was isolated and purified (FIG. 15A).

The structural gene for the E. coli catalytic subunit of aspartate transcarbamylase was isolated from pEK17 (FIG. 15A) (30). A 845 bp MseI/NruI fragment (denoted fragment 3) which contains all but the first 18 bp of the gene encoding ATCase was isolated and purified.

A synthetic fragment of DNA (denoted fragment 4) was constructed by annealing two complementary oligonucleotides and used to connect the bop and ATCase genes. The synthetic fragment was engineered to contain a HaeII site at the 5' terminus, a MseI site at the 3' terminus and an internal NruI site. Also included were nucleotides encoding: i) a unique protease site (i.e., blood clotting Factor X_(a)) and ii) ATCase amino acids 6 and 7 (relative to ATCase start codon) FIG. 17, SEQ ID NO:14.

All four DNA fragments were ligated together and used to transform E. coli strain D1210 (28) with selection for ampicillin resistance. Positive clones were identified by colony filter hybridization using P³² radiolabeled random primed (25) ATCase MseI/NruI fragment as probe. Positive clones were verified by restriction mapping and nucleotide sequencing. One positive clone was chosen and denoted pBATC (FIG. 15A).

Subsequently, the bop-ATCase fusion construct was adapted for H. halobium expression as follows. A fragment spanning the sequences in between and including the internal SphI site of the bop gene at the 5' terminus and the ATCase translational stop codon at the 3' terminus was isolated from pBATC by PCR (see FIG. 15B). In addition, the oligonucleotide used to construct the 3' terminus of this PCR fragment was designed to be complementary to bop sequences downstream of the transcriptional termination sequences and to include a unique BamHI to facilitate subsequent cloning steps. The resultant PCR fragment was digested with SphI/BamHI, purified and used in the following construction.

The plasmid, p1.2Kbbop, containing the bop gene and upstream sequences cloned in pUC19 (described above) was digested with SphI/BamHI to yield two fragments, a large one containing the vector and the majority of the bop gene, and a 358 bp fragment containing the C-terminal half of the bop gene (FIG. 15B). The larger of these two fragments was isolated, purified and ligated to the SphI/BamHI bop-ATCase PCR fragment A positive clone was isolated and confirmed by restriction mapping and nucleotide sequencing. This clone was digested with PstI/BamHI and a fragment containing DNA encoding the BR/ATCase fusion along with bop upstream regulatory sequences (FIG. 16) was cloned into the E. coli/H. halobium shuttle vector pUBP2. The resultant construct was named pBRAT (FIG. 15B). The nucleotide sequence (SEQ ID NO:14) and the translated amino acid sequence (SEQ ID NO:15) of this PstI/BamHI fragment is shown in FIG. 17.

2. Transformation of Halobacterium halobium

The PstI/BamHI fragments of the pENDs-Ser (FIG. 9 and 10, SEQ ID NO:10) and pBRAT (FIG. 15B, FIG. 16 and FIG. 17, SEQ ID NO:14) constructs containing the heterologous genes with the BR regulatory sequences were isolated and purified. Subsequently, these fragments were cloned into the E. coli/H. halobium shuttle vector pUBP2 (7) and transformed into H. halobium Bop deficient strain L33 as described (24).

Preferably, plasmids may be introduced into halobacteria using the polyethylene glycol (PEG) method (10, 11). Transformed halobacterial cells are then grown in culture in an appropriate nutrient medium sufficient to maintain the growth of halobacterial cells (7, 8).

H. halobium is prone to cell lysis during transformation procedures (7). Since surfactants are known to promote halobacterial lysis (21), all media and glassware used were soap-free. Transformation was performed according to Blaseio (7) and Cline (11) with modifications. Initially, cells were subcultured several times in soap-free complex (YET) medium. Subsequently, cells were subcultured to an OD₆₆₀ of about 0.01 and grown at 40° C. until the early to mid-logarithmic stage of growth (OD₆₆₀ of 0.4 to 0.6). All succeeding manipulations were performed at room temperature. The culture was removed from the waterbath shaker and incubated without agitation for 4 h to overnight, followed by centrifugation of 2 ml of culture at 1000×g for 15 min. The supernatant was carefully removed with a pipette and the interior of the centrifuge tube dried with absorbent tissue. The cell pellet was resuspended in 1/10 volume of spheroplasting solution (11), followed by addition of 1/100 volume of 0.5 M EDTA in Spheroplasting solution (11) and incubation for 2 min. One μg of DNA in 10 μl of spheroplasting solution was then added to the spheroplasted cells along with an equal volume of 60% PEG 600 (un-recrystallized) in spheroplasting solution. The combined solutions were gently but thoroughly mixed and then incubated for 20 min. Ten ml of 15% sucrose in complex (YET) medium was added followed by incubation overnight with no agitation at 42° C. The following day, cells were centrifuged at 3000×g for 15 minutes and resuspended in 300 μl of 15% sucrose in complex (YET) medium. This solution was plated on solid complex (YET) selection medium.

3. Analysis of transformants, expression of the heterologous polypeptide and assays for expression

To establish that halobacterial cells have been successfully transformed, various techniques may be employed. Where the expression vector used to transform the halobacteria contains a dominant selectable marker, transformed cells can be selected by growing in the appropriate selection medium such that growth of halobacterial cells not harboring the recombinant plasmid is inhibited. For example, where a plasmid containing the mevinolin resistance marker is used, halobacterial cells which harbor this plasmid may be selected by growing on solid nutrient medium containing mevinolin at a concentration in the range of 5 to 25 μM. Further, the plasmid may be isolated using standard techniques (12), restricted and used. The polymerase chain reaction, gel electrophoresis, restriction analysis, Southern, Northern, and Western blots may be employed, sequencing, or the like, may all be employed with advantage.

Depending upon the particular construct and the halobacterial background strain which have been employed for expression of the heterologous polypeptides, one may have constitutive or inducible expression of the heterologous polypeptide product. In the case of constitutive expression, the product will be continuously formed as the cells grow. By contrast, for inducible expression, one may provide for induction when the cells reach a predetermined cell density.

Where inducible promoters have been engineered into the expression vector containing the heterologous polypeptide DNA sequence, transcription may be induced using appropriate inducers under such conditions of concentration and duration as to effect induction of transcription. For example, if the regulatory sequences of the bacteriorhodopsin gene are used, transcription can be induced by low oxygen tension and high light intensity (18, 19) which are known to induce high level expression of BR. Low oxygen tensions are achieved in various ways such as by flushing culture flasks with oxygen-free nitrogen and sealing them, or by permitting cultures to reach the stationary phase of growth in which oxygen limitation occurs naturally (18). High light intensity of greater than about 100 mW/cm² can be achieved using various light sources and apparati as described (18, 19).

H. halobium transformed with pUBP2 containing the pBRAT PstI/BamHI fragment and with pUBP2 containing the pENDS-Ser PstI/BamHI fragment was plated on solid complex (YET) medium containing 25 μM mevinolin Plates were incubated for one to two weeks at 42° C. to permit growth of transformants. Plasmid DNA was isolated from individual transformants using Magic Minipreps DNA Purification System (Promega Corp., Madison, Wis.). Southern analysis was used to verify the presence of the heterologous gene on pUBP2. Southern blot analysis using the AlwNI/NotI fragment containing the serotonin receptor gene as probe indicated the presence of serotonin receptor gene sequences in all assayed transformants (FIG. 11). Total RNA was isolated from individual transformants using the RNAzol procedure (Cinna Biotech) and subjected to Northern analysis (18). Northern blot analysis revealed that transcription of Ser gene sequences had occurred (FIG. 12). Western analysis using both BR and ATCase antibodies demonstrated that the BR/ATCase fusion was expressed and localized to halobacterial membranes (FIG. 18). Washed halobacterial whole cell membranes were fractionated on sucrose gradients (FIG. 19A) and aliquots were subjected to SDS PAGE (FIG. 19B). A band corresponding to the predicted molecular weight of the fusion protein (i.e., ˜60 kDa, see FIG. 19B) was observed which derived from a purple fraction. These data verify expression of the fusion and indicate that the BR portion of the fusion is folded correctly in the halobacterial membrane. The presence of the BR chromophore (extinction coefficient of 63,000; 31) affords an estimate of 5 mg/liter of fusion protein expression.

Transformants testing positive in Southern and Northern analyses are subjected to Western analysis if specific antibodies to the heterologous protein are available. If antibodies are not available, DNA encoding an epitope known to be antigenic may be engineered into the expression vector construction to aid in detection of expression. An example of such an epitope is the sequence encoding Glu-Glu-Glu-Glu-Tyr-Met-Pro-Met-Glu (SEQ ID NO:5) (22). Alternatively, expression of the heterologous protein may be assayed functionally; for example, ligand binding assays for receptors, and assays for enzymic activity for soluble proteins using appropriate substrates.

4. Purification of heterologous polypeptides

Production of the heterologous polypeptide may be stopped in a variety of ways. Where the heterologous polypeptide is released into the medium, it may be isolated in a soluble or insoluble form using physical e.g. mechanical or thermal, or chemical treatments. Treatments employed may include freezing (≦0° C.), heating, hydrodynamic shearing, drying, selective filtration or precipitation by addition of acid, base, salts or organic solvents.

Where the expressed heterologous polypeptide resides in the membrane or in the cytoplasm, cells are harvested to separate them from the culture medium. Various techniques may be used for harvesting, desirably using centrifugation. The supernatant may then be discarded and the cell pellet washed with an appropriate buffered aqueous medium to remove any residual culture medium components. Typically the buffered medium will be at a temperature in the range of about 1 to 10° C., more usually 4° C.

The cells may be lysed by any convenient means, such as freezing and mechanical, use of hypotonic solutions (23), and the like. The resulting dispersion of disrupted cells is then treated by such means as to substantially separate cell membranes from soluble proteins and other contaminants. Several techniques may be employed to advantage for isolating membranes including differential centrifugation, density gradient centrifugation, and the like. This membrane isolation separates the fusion protein from the bulk of the soluble proteins.

Heterologous polypeptides are purified according to procedures dependent on their individual properties and those of BR. Where the expressed soluble heterologous polypeptide is fused at the C-terminal region of BR, advantage may be taken of the likelihood that the BR domain will anchor the fusion protein in the membrane.

Where the heterologous polypeptide is expressed as a fusion polypeptide linked to the C-terminal region, or fragment thereof, of the bacteriorhodopsin gene with a unique protease site between said heterologous polypeptide and C-terminal region, the heterologous polypeptide may be isolated by incubating the halobacterial membranes with an appropriate unique protease to effect substantially complete cleavage at the protease cleavage site. For example, where the heterologous polypeptide is linked to the bacteriorhodopsin C-terminal region through the amino acid sequence Ile-Glu-Gly-Arg (SEQ ID NO:4), cell membranes are incubated with factor X_(a) under conditions recommended by the manufacturers. Factor X_(a) is dissolved in redistilled water to a final protein concentration of 1 mg/ml. The fusion protein to be cleaved is dissolved in 100 mM NaCl, 50 mM Tris-HCl, 1 mM CaCl₂, pH 8.0. To increase the solubility of the substrate, urea or acetonitrile can be added up to a final concentration of 1 M and 10% (v/v), respectively without significant inhibition of the enzyme activity. The recommended amount of enzyme is 1/200 to 1/10 of the substrate by weight. Incubation should be carried out at 4° C. to 25° C. for 1-18 h. The optimum cleavage conditions have to be determined for each fusion protein. The release of the desired polypeptide from the fusion protein is influenced by the adjacent amino acid sequences at the cleavage site, the size of the two fused polypeptide components, and the accessibility of the cleavage site. Protease treatment is followed by standard purification protocols to remove the minor unique protease component.

If further purification of the heterologous polypeptide protein is desired, antibodies specific for the heterologous polypeptide, ligand affinity, electrophoresis, chromatography, zonal centrifugation, and the like, may be employed to advantage. The product may then be dried by any convenient means, such as freeze drying, spray drying, and the like, or alternatively suspended in an appropriate buffered aqueous solution. The heterologous polypeptide product is then ready for use.

5. Bioassays

The heterologous polypeptides may be assayed using protocols dependent on their individual properties. For example, receptors are assayed using ligand binding assays. Soluble proteins having enzyme activity are assayed using appropriate substrates.

Bibliography

For the sake of convenience, various documents referenced in the body of the present specification are grouped in the following bibliography by number that corresponds to the parenthetical number of that reference in the text. Each of these documents is hereby expressly incorporated by reference.

1. Gropp Syst. Appl. Microbiol. 7, 95 (1986).

2. Zillig Eur. J. Biochem. 173, 473 (1988).

3. Dennis J. Bacteriol. 168, 471 (1986).

4. Oesterhelt Proc. Nat. Acad. Sci. USA 70, 2853 (1971).

5. Henderson Annu. Rev. Biophys. Bioenerg. 6, 87 (1977).

6. Katre Proc. Natl. Acad. Sci. USA 78, 4068 (1981)

7. Blasieo Proc. natl. Acad. Sci. USA 87, 6772 (1990)

8. Holmes J. Bacteriol. 172, 756 (1990)

9. Ni Gene 90, 169 (1990).

10. Charlebois Proc. Natl. Acad. Sci. usa 84, 8530 (1987)

11. Cline J. bacterial. 169, 1341 (1987)

12. Maniatis "Molecular Cloning: A Laboratory Manual". Cold Spring Harbor Laboratory, CSH, N.Y. (1989)

13. Betlach Nucl. Acids Res. 12, 7949 (1984)

14. Leong J. bacteriol. 170, 4903 (1988)

15. Wagner FEBS Letters 131, 341 (1983)

16. Spudich Proc. Natl. Acad. Sci. USA, 79 4398 (1982)

17. Pfeifer J. Bacteriol. 145, 375 (1981)

18. Shand J. Bacteriol. 173, 4692 (1991)

19. Betlach, In: "Protocols for Archael Research". Robb & Das Sarma (Eds.), Cold Spring Harbor Laboratory. Cold Spring Harbor, N.Y., in press (1993)

20. Yanisch-Perron Gene 33, 103 (1985)

21. Kamekura Appl. Environmental Microbiol. 54, 990 (1988)

22. Grussenmeyer Proc. Natl. Acad.Sci. USA 82 7952 (1985)

23. Turner Biochemistry 32 1332 (1993)

24. Cline Can. J. Microbiol., 35, 148 (1989)

25. Feinberg Analytical Biochemistry 132 6 (1983)

26. Hoffmann Nucleic Acids Research 19 6337 (1991)

27. Julius Science 241 558 (1988)

28. Kuhn Gene 44 253 (1986)

29. Kunkel Methods Enzymol. 154 367 (1987)

30. Nowlan J. Biol. Chem. 260 14712 (1985)

31. Power Gene 113 95 (1992)

32. Shand Biochemistry 30 3082 (1991)

33. Vu Cell 64 1057 (1991)

Concluding Remarks

The foregoing description details specific methods that can be employed to practice the present invention. Having detailed specific methods initially used to construct and use vectors for the expression, isolation, detection and further purification of heterologous polypeptides in halobacteria, those skilled in the art will know how to devise alternative reliable methods for arriving at the same and equivalent systems described herein. The foregoing should not be construed as limiting the overall scope hereof; rather, the ambit of the present invention is to be governed only by the lawful interpretation of the appended claims.

    __________________________________________________________________________     #             SEQUENCE LISTING                                                 - (1) GENERAL INFORMATION:                                                     -    (iii) NUMBER OF SEQUENCES: 15                                             - (2) INFORMATION FOR SEQ ID NO:1:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 1254 base                                                          (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: double                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: DNA (genomic)                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 376..414                                               #/note= "BacteriorhodopsinATION:                                                              pre-sequence - #."                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: CDS                                                              (B) LOCATION: 376..1161                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 3..8                                                   #/note= "PstI site."INFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1245..1250                                             #/note= "BamHI site."NFORMATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #signal                                            (B) LOCATION: 374                                                    #/note= "RNA start site."MATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 9..414                                                 #/note= "BacteriorhodopsinATION:                                                              transcriptio - #nal and translational regulatory                #are located in this region."                                                  -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:1:                                  - ATCTGCAGGA TGGGTGCAAC CGTGAAGTCC GTCACGGCTG CGTCACGACA GG - #AGCCGACC          60                                                                           - AGCGACACCC AGAAGGTGCG AACGGTTGAG TGCCGCAACG ATCACGAGTT TT - #TCGTGCGC         120                                                                           - TTCGAGTGGT AACACGCGTG CACGCATCGA CTTCACCGCG GGTGTTTCGA CG - #CCAGCCGG         180                                                                           - CCGTTGAACC AGCAGGCAGC GGGCATTTCA CAGCCGCTGT GGCCCACACA CT - #CGGTGGGG         240                                                                           - TGCGCTATTT TGGTATGGTT TGGAATCCGC GTGTCGGCTC CGTGTCTGAC GG - #TTCATCGG         300                                                                           - TCTAAATTCC GTCACGAGCG TACCATACTG ATTGGGTCGT AGAGTTACAC AC - #ATATCCTC         360                                                                           #GCA GTG GAG GGG GTA     411AG TTA TTG CCA ACA                                 #Leu Glu Leu Leu Pro Thr Ala Val Glu Gly V - #al                               #                10                                                            - TCG CAG GCC CAG ATC ACC GGA CGT CCG GAG TG - #G ATC TGG CTA GCG CTC           459                                                                           Ser Gln Ala Gln Ile Thr Gly Arg Pro Glu Tr - #p Ile Trp Leu Ala Leu            #         25                                                                   - GGT ACG GCG CTA ATG GGA CTC GGG ACG CTC TA - #T TTC CTC GTG AAA GGG           507                                                                           Gly Thr Ala Leu Met Gly Leu Gly Thr Leu Ty - #r Phe Leu Val Lys Gly            #     40                                                                       - ATG GGC GTC TCG GAC CCA GAT GCA AAG AAA TT - #C TAC GCC ATC ACG ACG           555                                                                           Met Gly Val Ser Asp Pro Asp Ala Lys Lys Ph - #e Tyr Ala Ile Thr Thr            # 60                                                                           - CTC GTC CCA GCC ATC GCG TTC ACG ATG TAC CT - #C TCG ATG CTG CTG GGG           603                                                                           Leu Val Pro Ala Ile Ala Phe Thr Met Tyr Le - #u Ser Met Leu Leu Gly            #                 75                                                           - TAT GGC CTC ACA ATG GTA CCG TTC GGT GGG GA - #G CAG AAC CCC ATC TAC           651                                                                           Tyr Gly Leu Thr Met Val Pro Phe Gly Gly Gl - #u Gln Asn Pro Ile Tyr            #             90                                                               - TGG GCG CGG TAC GCT GAC TGG CTG TTC ACC AC - #G CCG CTG TTG TTG TTA           699                                                                           Trp Ala Arg Tyr Ala Asp Trp Leu Phe Thr Th - #r Pro Leu Leu Leu Leu            #        105                                                                   - GAC CTC GCG TTG CTC GTT GAC GCG GAT CAG GG - #A ACG ATC CTT GCG CTC           747                                                                           Asp Leu Ala Leu Leu Val Asp Ala Asp Gln Gl - #y Thr Ile Leu Ala Leu            #   120                                                                        - GTC GGT GCC GAC GGC ATC ATG ATC GGG ACC GG - #C CTG GTC GGC GCA CTG           795                                                                           Val Gly Ala Asp Gly Ile Met Ile Gly Thr Gl - #y Leu Val Gly Ala Leu            125                 1 - #30                 1 - #35                 1 -        #40                                                                            - ACG AAG GTC TAC TCG TAC CGC TTC GTG TGG TG - #G GCG ATC AGC ACC GCA           843                                                                           Thr Lys Val Tyr Ser Tyr Arg Phe Val Trp Tr - #p Ala Ile Ser Thr Ala            #               155                                                            - GCG ATG CTG TAC ATC CTG TAC GTG CTG TTC TT - #C GGG TTC ACC TCG AAG           891                                                                           Ala Met Leu Tyr Ile Leu Tyr Val Leu Phe Ph - #e Gly Phe Thr Ser Lys            #           170                                                                - GCC GAA AGC ATG CGC CCC GAG GTC GCA TCC AC - #G TTC AAA GTA CTG CGT           939                                                                           Ala Glu Ser Met Arg Pro Glu Val Ala Ser Th - #r Phe Lys Val Leu Arg            #       185                                                                    - AAC GTT ACC GTT GTG TTG TGG TCC GCG TAT CC - #C GTC GTG TGG CTG ATC           987                                                                           Asn Val Thr Val Val Leu Trp Ser Ala Tyr Pr - #o Val Val Trp Leu Ile            #   200                                                                        - GGC AGC GAA GGT GCG GGA ATC GTG CCG CTG AA - #C ATC GAG ACG CTG CTG          1035                                                                           Gly Ser Glu Gly Ala Gly Ile Val Pro Leu As - #n Ile Glu Thr Leu Leu            205                 2 - #10                 2 - #15                 2 -        #20                                                                            - TTC ATG GTG CTT GAC GTG AGC GCG AAG GTC GG - #C TTC GGG CTC ATC CTC          1083                                                                           Phe Met Val Leu Asp Val Ser Ala Lys Val Gl - #y Phe Gly Leu Ile Leu            #               235                                                            - CTG CGC AGT CGT GCG ATC TTC GGC GAA GCC GA - #A GCG CCG GAG CCG TCC          1131                                                                           Leu Arg Ser Arg Ala Ile Phe Gly Glu Ala Gl - #u Ala Pro Glu Pro Ser            #           250                                                                - GCC GGC GAC GGC GCG GCC GCG ACC AGC GAC TG - #ATCGCACA CGCAGGACAG            1181                                                                           Ala Gly Asp Gly Ala Ala Ala Thr Ser Asp                                        #       260                                                                    - CCCCACAACC GGCGCGGCTG TGTTCAACGA CACACGATGA GTCCCCCACT CG - #GTCTTGTA        1241                                                                           #    1254                                                                      - (2) INFORMATION FOR SEQ ID NO:2:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #acids    (A) LENGTH: 262 amino                                                          (B) TYPE: amino acid                                                           (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: protein                                              -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:                                  - Met Leu Glu Leu Leu Pro Thr Ala Val Glu Gl - #y Val Ser Gln Ala Gln          #                 15                                                           - Ile Thr Gly Arg Pro Glu Trp Ile Trp Leu Al - #a Leu Gly Thr Ala Leu          #             30                                                               - Met Gly Leu Gly Thr Leu Tyr Phe Leu Val Ly - #s Gly Met Gly Val Ser          #         45                                                                   - Asp Pro Asp Ala Lys Lys Phe Tyr Ala Ile Th - #r Thr Leu Val Pro Ala          #     60                                                                       - Ile Ala Phe Thr Met Tyr Leu Ser Met Leu Le - #u Gly Tyr Gly Leu Thr          # 80                                                                           - Met Val Pro Phe Gly Gly Glu Gln Asn Pro Il - #e Tyr Trp Ala Arg Tyr          #                 95                                                           - Ala Asp Trp Leu Phe Thr Thr Pro Leu Leu Le - #u Leu Asp Leu Ala Leu          #           110                                                                - Leu Val Asp Ala Asp Gln Gly Thr Ile Leu Al - #a Leu Val Gly Ala Asp          #       125                                                                    - Gly Ile Met Ile Gly Thr Gly Leu Val Gly Al - #a Leu Thr Lys Val Tyr          #   140                                                                        - Ser Tyr Arg Phe Val Trp Trp Ala Ile Ser Th - #r Ala Ala Met Leu Tyr          145                 1 - #50                 1 - #55                 1 -        #60                                                                            - Ile Leu Tyr Val Leu Phe Phe Gly Phe Thr Se - #r Lys Ala Glu Ser Met          #               175                                                            - Arg Pro Glu Val Ala Ser Thr Phe Lys Val Le - #u Arg Asn Val Thr Val          #           190                                                                - Val Leu Trp Ser Ala Tyr Pro Val Val Trp Le - #u Ile Gly Ser Glu Gly          #       205                                                                    - Ala Gly Ile Val Pro Leu Asn Ile Glu Thr Le - #u Leu Phe Met Val Leu          #   220                                                                        - Asp Val Ser Ala Lys Val Gly Phe Gly Leu Il - #e Leu Leu Arg Ser Arg          225                 2 - #30                 2 - #35                 2 -        #40                                                                            - Ala Ile Phe Gly Glu Ala Glu Ala Pro Glu Pr - #o Ser Ala Gly Asp Gly          #               255                                                            - Ala Ala Ala Thr Ser Asp                                                                  260                                                                - (2) INFORMATION FOR SEQ ID NO:3:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #acids    (A) LENGTH: 248 amino                                                          (B) TYPE: amino acid                                                           (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: protein                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: Region                                                           (B) LOCATION: 225..248                                               #/note= "Cytoplasmic C-terminal:                                                              region of - # bacteriorhodopsin."                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: Region                                                           (B) LOCATION: 1                                                      #/note= "Pyroglutamate."RMATION:                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:                                  - Xaa Ala Gln Ile Thr Gly Arg Pro Glu Trp Il - #e Trp Leu Ala Leu Gly          #                15                                                            - Thr Ala Leu Met Gly Leu Gly Thr Leu Tyr Ph - #e Leu Val Lys Gly Met          #            30                                                                - Gly Val Ser Asp Pro Asp Ala Lys Lys Phe Ty - #r Ala Ile Thr Thr Leu          #        45                                                                    - Val Pro Ala Ile Ala Phe Thr Met Tyr Leu Se - #r Met Leu Leu Gly Tyr          #    60                                                                        - Gly Leu Thr Met Val Pro Phe Gly Gly Glu Gl - #n Asn Pro Ile Tyr Trp          #80                                                                            - Ala Arg Tyr Ala Asp Trp Leu Phe Thr Thr Pr - #o Leu Leu Leu Leu Asp          #                95                                                            - Leu Ala Leu Leu Val Asp Ala Asp Gln Gly Th - #r Ile Leu Ala Leu Val          #           110                                                                - Gly Ala Asp Gly Ile Met Ile Gly Thr Gly Le - #u Val Gly Ala Leu Thr          #       125                                                                    - Lys Val Tyr Ser Tyr Arg Phe Val Trp Trp Al - #a Ile Ser Thr Ala Ala          #   140                                                                        - Met Leu Tyr Ile Leu Tyr Val Leu Phe Phe Gl - #y Phe Thr Ser Lys Ala          145                 1 - #50                 1 - #55                 1 -        #60                                                                            - Glu Ser Met Arg Pro Glu Val Ala Ser Thr Ph - #e Lys Val Leu Arg Asn          #               175                                                            - Val Thr Val Val Leu Trp Ser Ala Tyr Pro Va - #l Val Trp Leu Ile Gly          #           190                                                                - Ser Glu Gly Ala Gly Ile Val Pro Leu Asn Il - #e Glu Thr Leu Leu Phe          #       205                                                                    - Met Val Leu Asp Val Ser Ala Lys Val Gly Ph - #e Gly Leu Ile Leu Leu          #   220                                                                        - Arg Ser Arg Ala Ile Phe Gly Glu Ala Glu Al - #a Pro Glu Pro Ser Ala          225                 2 - #30                 2 - #35                 2 -        #40                                                                            - Gly Asp Gly Ala Ala Ala Thr Ser                                                              245                                                            - (2) INFORMATION FOR SEQ ID NO:4:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #acids    (A) LENGTH: 4 amino                                                            (B) TYPE: amino acid                                                           (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: peptide                                              -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:4:                                  - Ile Glu Gly Arg                                                              - (2) INFORMATION FOR SEQ ID NO:5:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #acids    (A) LENGTH: 9 amino                                                            (B) TYPE: amino acid                                                           (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: peptide                                              -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:5:                                  - Glu Glu Glu Glu Tyr Met Pro Met Glu                                          1               5                                                              - (2) INFORMATION FOR SEQ ID NO:6:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 1956 base                                                          (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: cDNA                                                 -     (ix) FEATURE:                                                                      (A) NAME/KEY: CDS                                                              (B) LOCATION: 376..1812                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 376..414                                               #/note= "BacteriorhodopsinATION:                                                              pre-sequence - #."                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: terminator                                                       (B) LOCATION: 1864..1866                                             #/note= "Bacteriorhodopsin stop:                                                              codon."                                                         -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(213, - # "")                                   #/note= "G to T mutation removes                                                              AlwNI res - #triction site."                                    -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 427..435                                               #/note= "AlwNI cloning site."ON:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(930, - # "")                                   #/note= "G to A mutation removes                                                              AlwNI res - #triction site."                                    -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(1179 - #, "")                                  #/note= "T to A mutation removes                                                              AlwNI sit - #e."                                                -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(1245 - #, "")                                  #/note= "G to A mutation removes                                                              PstI rest - #riction site."                                     -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #signal                                            (B) LOCATION: 374                                                    #/note= "RNA start site."MATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(1863 - #, "")                                  #/note= "C to T mutation removes                                                              AlwNI res - #triction site."                                    -     (ix) FEATURE:                                                                      (A) NAME/KEY: terminator                                                       (B) LOCATION: 1813..1815                                             #/note= "Muscarinic "OM1" stopN:                                                              codon."                                                         -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:6:                                  - ATCTGCAGGA TGGGTGCAAC CGTGAAGTCC GTCACGGCTG CGTCACGACA GG - #AGCCGACC          60                                                                           - AGCGACACCC AGAAGGTGCG AACGGTTGAG TGCCGCAACG ATCACGAGTT TT - #TCGTGCGC         120                                                                           - TTCGAGTGGT AACACGCGTG CACGCATCGA CTTCACCGCG GGTGTTTCGA CG - #CCAGCCGG         180                                                                           - CCGTTGAACC AGCAGGCAGC GGGCATTTCA CATCCGCTGT GGCCCACACA CT - #CGGTGGGG         240                                                                           - TGCGCTATTT TGGTATGGTT TGGAATCCGC GTGTCGGCTC CGTGTCTGAC GG - #TTCATCGG         300                                                                           - TCTAAATTCC GTCACGAGCG TACCATACTG ATTGGGTCGT AGAGTTACAC AC - #ATATCCTC         360                                                                           #GCA GTG GAG GGG GTA     411AG TTA TTG CCA ACA                                 #Leu Glu Leu Leu Pro Thr Ala Val Glu Gly V - #al                               #                10                                                            - TCG CAG GCC CAG ATC CAG GCG CTG ATG AAC AC - #T TCA GCC CCA CCT GCT           459                                                                           Ser Gln Ala Gln Ile Gln Ala Leu Met Asn Th - #r Ser Ala Pro Pro Ala            #         25                                                                   - GTC AGC CCC AAC ATC ACC GTC CTG GCA CCA GG - #A AAG GGT CCC TGG CAA           507                                                                           Val Ser Pro Asn Ile Thr Val Leu Ala Pro Gl - #y Lys Gly Pro Trp Gln            #     40                                                                       - GTG GCC TTC ATT GGG ATC ACC ACG GGC CTC CT - #G TCG CTA GCC ACA GTG           555                                                                           Val Ala Phe Ile Gly Ile Thr Thr Gly Leu Le - #u Ser Leu Ala Thr Val            # 60                                                                           - ACA GGC AAC CTG CTG GTA CTC ATC TCT TTC AA - #G GTC AAC ACG GAG CTC           603                                                                           Thr Gly Asn Leu Leu Val Leu Ile Ser Phe Ly - #s Val Asn Thr Glu Leu            #                 75                                                           - AAG ACA GTC AAT AAC TAC TTC CTG CTG AGC CT - #G GCC TGT GCT GAC CTC           651                                                                           Lys Thr Val Asn Asn Tyr Phe Leu Leu Ser Le - #u Ala Cys Ala Asp Leu            #             90                                                               - ATC ATC GGT ACC TTC TCC ATG AAC CTC TAT AC - #C ACG TAC CTG CTC ATG           699                                                                           Ile Ile Gly Thr Phe Ser Met Asn Leu Tyr Th - #r Thr Tyr Leu Leu Met            #        105                                                                   - GGC CAC TGG GCT CTG GGC ACG CTG GCT TGT GA - #C CTC TGG CTG GCC CTG           747                                                                           Gly His Trp Ala Leu Gly Thr Leu Ala Cys As - #p Leu Trp Leu Ala Leu            #   120                                                                        - GAC TAT GTG GCC AGC AAT GCC TCC GTC ATG AA - #T CTG CTG CTC ATC AGC           795                                                                           Asp Tyr Val Ala Ser Asn Ala Ser Val Met As - #n Leu Leu Leu Ile Ser            125                 1 - #30                 1 - #35                 1 -        #40                                                                            - TTT GAC CGC TAC TTC TCC GTG ACT CGG CCC CT - #G AGC TAC CGT GCC AAG           843                                                                           Phe Asp Arg Tyr Phe Ser Val Thr Arg Pro Le - #u Ser Tyr Arg Ala Lys            #               155                                                            - CGC ACA CCC CGC CGC GCA GCT CTG ATG ATC GG - #C CTG GCC TGG CTG GTT           891                                                                           Arg Thr Pro Arg Arg Ala Ala Leu Met Ile Gl - #y Leu Ala Trp Leu Val            #           170                                                                - TCC TTT GTG CTC TGG GCC CCA GCC ATC CTC TT - #C TGG CAA TAC CTG GTA           939                                                                           Ser Phe Val Leu Trp Ala Pro Ala Ile Leu Ph - #e Trp Gln Tyr Leu Val            #       185                                                                    - GGG GAG CGG ACG ATG CTA GCT GGG CAG TGC TA - #C ATC CAG TTC CTC TCC           987                                                                           Gly Glu Arg Thr Met Leu Ala Gly Gln Cys Ty - #r Ile Gln Phe Leu Ser            #   200                                                                        - CAG CCC ATC ATC ACC TTT GGC ACA GCC ATG GC - #T GCC TTC TAC CTC CCT          1035                                                                           Gln Pro Ile Ile Thr Phe Gly Thr Ala Met Al - #a Ala Phe Tyr Leu Pro            205                 2 - #10                 2 - #15                 2 -        #20                                                                            - GTC ACA GTC ATG TGC ACG CTC TAC TGG CGC AT - #C TAC CGG GAG ACA GAG          1083                                                                           Val Thr Val Met Cys Thr Leu Tyr Trp Arg Il - #e Tyr Arg Glu Thr Glu            #               235                                                            - AAC CGA GCA CGG GAG CTG GCA GCC CTT CAG GG - #C TCC GAG ACG CCA GGC          1131                                                                           Asn Arg Ala Arg Glu Leu Ala Ala Leu Gln Gl - #y Ser Glu Thr Pro Gly            #           250                                                                - AAA GGG GGT GGC AGC AGC AGC AGC TCA GAG AG - #G TCT CAG CCA GGG GCA          1179                                                                           Lys Gly Gly Gly Ser Ser Ser Ser Ser Glu Ar - #g Ser Gln Pro Gly Ala            #       265                                                                    - GAG GGC TCA CCA GAG ACT CCT CCA GGC CGC TG - #C TGT CGC TGC TGC CGG          1227                                                                           Glu Gly Ser Pro Glu Thr Pro Pro Gly Arg Cy - #s Cys Arg Cys Cys Arg            #   280                                                                        - GCC CCA AGG CTG CTG CAA GCC TAC AGC TGG AA - #G GAA GAA GAG GAA GAG          1275                                                                           Ala Pro Arg Leu Leu Gln Ala Tyr Ser Trp Ly - #s Glu Glu Glu Glu Glu            285                 2 - #90                 2 - #95                 3 -        #00                                                                            - GAC GAA GGC TCC ATG GAG TCC CTC ACA TCC TC - #A GAG GGA GAG GAG CCT          1323                                                                           Asp Glu Gly Ser Met Glu Ser Leu Thr Ser Se - #r Glu Gly Glu Glu Pro            #               315                                                            - GGC TCC GAA GTG GTG ATC AAG ATG CCA ATG GT - #G GAC CCC GAG GCA CAG          1371                                                                           Gly Ser Glu Val Val Ile Lys Met Pro Met Va - #l Asp Pro Glu Ala Gln            #           330                                                                - GCC CCC ACC AAG CAG CCC CCA CGG AGC TCC CC - #A AAT ACA GTC AAG AGG          1419                                                                           Ala Pro Thr Lys Gln Pro Pro Arg Ser Ser Pr - #o Asn Thr Val Lys Arg            #       345                                                                    - CCG ACT AAG AAA GGG CGT GAT CGA GCT GGC AA - #G GGC CAG AAG CCC CGT          1467                                                                           Pro Thr Lys Lys Gly Arg Asp Arg Ala Gly Ly - #s Gly Gln Lys Pro Arg            #   360                                                                        - GGA AAG GAG CAG CTG GCC AAG CGG AAG ACC TT - #C TCG CTG GTC AAG GAG          1515                                                                           Gly Lys Glu Gln Leu Ala Lys Arg Lys Thr Ph - #e Ser Leu Val Lys Glu            365                 3 - #70                 3 - #75                 3 -        #80                                                                            - AAG AAG GCG GCT CGG ACC CTG AGT GCC ATC CT - #C CTG GCC TTC ATC CTC          1563                                                                           Lys Lys Ala Ala Arg Thr Leu Ser Ala Ile Le - #u Leu Ala Phe Ile Leu            #               395                                                            - ACC TGG ACA CCG TAC AAC ATC ATG GTG CTG GT - #G TCC ACC TTC TGC AAG          1611                                                                           Thr Trp Thr Pro Tyr Asn Ile Met Val Leu Va - #l Ser Thr Phe Cys Lys            #           410                                                                - GAC TGT GTT CCC GAG ACC CTG TGG GAG CTG GG - #C TAC TGG CTG TGC TAC          1659                                                                           Asp Cys Val Pro Glu Thr Leu Trp Glu Leu Gl - #y Tyr Trp Leu Cys Tyr            #       425                                                                    - GTC AAC AGC ACC ATC AAC CCC ATG TGC TAC GC - #A CTC TGC AAC AAA GCC          1707                                                                           Val Asn Ser Thr Ile Asn Pro Met Cys Tyr Al - #a Leu Cys Asn Lys Ala            #   440                                                                        - TTC CGG GAC ACC TTT CGC CTG CTG CTT TGC CG - #C TGG GAC AAG AGA CGC          1755                                                                           Phe Arg Asp Thr Phe Arg Leu Leu Leu Cys Ar - #g Trp Asp Lys Arg Arg            445                 4 - #50                 4 - #55                 4 -        #60                                                                            - TGG CGC AAG ATC CCC AAG CGC CCT GGC TCC GT - #G CAC CGC ACT CCC TCC          1803                                                                           Trp Arg Lys Ile Pro Lys Arg Pro Gly Ser Va - #l His Arg Thr Pro Ser            #               475                                                            - CGC CAA TGC TGATAGTCCC CTCTCCTGCA TCCCTCCACC CCAGCGGCC - #G                  1852                                                                           Arg Gln Cys                                                                    - CGACCAGCGA TTGATCGCAC ACGCAGGACA GCCCCACAAC CGGCGCGGCT GT - #GTTCAACG        1912                                                                           #                 195 - #6GGTCTTGT ACTCGGATCC TTTT                             - (2) INFORMATION FOR SEQ ID NO:7:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #acids    (A) LENGTH: 479 amino                                                          (B) TYPE: amino acid                                                           (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: protein                                              -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:7:                                  - Met Leu Glu Leu Leu Pro Thr Ala Val Glu Gl - #y Val Ser Gln Ala Gln          #                 15                                                           - Ile Gln Ala Leu Met Asn Thr Ser Ala Pro Pr - #o Ala Val Ser Pro Asn          #             30                                                               - Ile Thr Val Leu Ala Pro Gly Lys Gly Pro Tr - #p Gln Val Ala Phe Ile          #         45                                                                   - Gly Ile Thr Thr Gly Leu Leu Ser Leu Ala Th - #r Val Thr Gly Asn Leu          #     60                                                                       - Leu Val Leu Ile Ser Phe Lys Val Asn Thr Gl - #u Leu Lys Thr Val Asn          # 80                                                                           - Asn Tyr Phe Leu Leu Ser Leu Ala Cys Ala As - #p Leu Ile Ile Gly Thr          #                 95                                                           - Phe Ser Met Asn Leu Tyr Thr Thr Tyr Leu Le - #u Met Gly His Trp Ala          #           110                                                                - Leu Gly Thr Leu Ala Cys Asp Leu Trp Leu Al - #a Leu Asp Tyr Val Ala          #       125                                                                    - Ser Asn Ala Ser Val Met Asn Leu Leu Leu Il - #e Ser Phe Asp Arg Tyr          #   140                                                                        - Phe Ser Val Thr Arg Pro Leu Ser Tyr Arg Al - #a Lys Arg Thr Pro Arg          145                 1 - #50                 1 - #55                 1 -        #60                                                                            - Arg Ala Ala Leu Met Ile Gly Leu Ala Trp Le - #u Val Ser Phe Val Leu          #               175                                                            - Trp Ala Pro Ala Ile Leu Phe Trp Gln Tyr Le - #u Val Gly Glu Arg Thr          #           190                                                                - Met Leu Ala Gly Gln Cys Tyr Ile Gln Phe Le - #u Ser Gln Pro Ile Ile          #       205                                                                    - Thr Phe Gly Thr Ala Met Ala Ala Phe Tyr Le - #u Pro Val Thr Val Met          #   220                                                                        - Cys Thr Leu Tyr Trp Arg Ile Tyr Arg Glu Th - #r Glu Asn Arg Ala Arg          225                 2 - #30                 2 - #35                 2 -        #40                                                                            - Glu Leu Ala Ala Leu Gln Gly Ser Glu Thr Pr - #o Gly Lys Gly Gly Gly          #               255                                                            - Ser Ser Ser Ser Ser Glu Arg Ser Gln Pro Gl - #y Ala Glu Gly Ser Pro          #           270                                                                - Glu Thr Pro Pro Gly Arg Cys Cys Arg Cys Cy - #s Arg Ala Pro Arg Leu          #       285                                                                    - Leu Gln Ala Tyr Ser Trp Lys Glu Glu Glu Gl - #u Glu Asp Glu Gly Ser          #   300                                                                        - Met Glu Ser Leu Thr Ser Ser Glu Gly Glu Gl - #u Pro Gly Ser Glu Val          305                 3 - #10                 3 - #15                 3 -        #20                                                                            - Val Ile Lys Met Pro Met Val Asp Pro Glu Al - #a Gln Ala Pro Thr Lys          #               335                                                            - Gln Pro Pro Arg Ser Ser Pro Asn Thr Val Ly - #s Arg Pro Thr Lys Lys          #           350                                                                - Gly Arg Asp Arg Ala Gly Lys Gly Gln Lys Pr - #o Arg Gly Lys Glu Gln          #       365                                                                    - Leu Ala Lys Arg Lys Thr Phe Ser Leu Val Ly - #s Glu Lys Lys Ala Ala          #   380                                                                        - Arg Thr Leu Ser Ala Ile Leu Leu Ala Phe Il - #e Leu Thr Trp Thr Pro          385                 3 - #90                 3 - #95                 4 -        #00                                                                            - Tyr Asn Ile Met Val Leu Val Ser Thr Phe Cy - #s Lys Asp Cys Val Pro          #               415                                                            - Glu Thr Leu Trp Glu Leu Gly Tyr Trp Leu Cy - #s Tyr Val Asn Ser Thr          #           430                                                                - Ile Asn Pro Met Cys Tyr Ala Leu Cys Asn Ly - #s Ala Phe Arg Asp Thr          #       445                                                                    - Phe Arg Leu Leu Leu Cys Arg Trp Asp Lys Ar - #g Arg Trp Arg Lys Ile          #   460                                                                        - Pro Lys Arg Pro Gly Ser Val His Arg Thr Pr - #o Ser Arg Gln Cys              465                 4 - #70                 4 - #75                            - (2) INFORMATION FOR SEQ ID NO:8:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 1581 base                                                          (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: cDNA                                                 -     (ix) FEATURE:                                                                      (A) NAME/KEY: CDS                                                              (B) LOCATION: 376..1437                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 376..414                                               #/note= "BacteriorhodopsinATION:                                                              pre-sequence - #."                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: terminator                                                       (B) LOCATION: 1489..1491                                             #/note= "Bacteriorhodopsin stop:                                                              codon."                                                         -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(213, - # "")                                   #/note= "G to T mutation removes                                                              AlwNI res - #triction site."                                    -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 427..435                                               #/note= "AlwNI cloning site."ON:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(930, - # "")                                   #/note= "G to A mutation removes                                                              AlwNI sit - #e."                                                -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #signal                                            (B) LOCATION: 374                                                    #/note= "RNA start site."MATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: terminator                                                       (B) LOCATION: 1438..1440                                             #/note= "Muscarinic stop codon."                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(1488 - #, "")                                  #/note= "C to T mutation removes                                                              AlwNI res - #triction site."                                    -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:8:                                  - ATCTGCAGGA TGGGTGCAAC CGTGAAGTCC GTCACGGCTG CGTCACGACA GG - #AGCCGACC          60                                                                           - AGCGACACCC AGAAGGTGCG AACGGTTGAG TGCCGCAACG ATCACGAGTT TT - #TCGTGCGC         120                                                                           - TTCGAGTGGT AACACGCGTG CACGCATCGA CTTCACCGCG GGTGTTTCGA CG - #CCAGCCGG         180                                                                           - CCGTTGAACC AGCAGGCAGC GGGCATTTCA CATCCGCTGT GGCCCACACA CT - #CGGTGGGG         240                                                                           - TGCGCTATTT TGGTATGGTT TGGAATCCGC GTGTCGGCTC CGTGTCTGAC GG - #TTCATCGG         300                                                                           - TCTAAATTCC GTCACGAGCG TACCATACTG ATTGGGTCGT AGAGTTACAC AC - #ATATCCTC         360                                                                           #GCA GTG GAG GGG GTA     411AG TTA TTG CCA ACA                                 #Leu Glu Leu Leu Pro Thr Ala Val Glu Gly V - #al                               #                10                                                            - TCG CAG GCC CAG ATC CAG GCG CTG ATG AAC AC - #T TCA GCC CCA CCT GCT           459                                                                           Ser Gln Ala Gln Ile Gln Ala Leu Met Asn Th - #r Ser Ala Pro Pro Ala            #         25                                                                   - GTC AGC CCC AAC ATC ACC GTC CTG GCA CCA GG - #A AAG GGT CCC TGG CAA           507                                                                           Val Ser Pro Asn Ile Thr Val Leu Ala Pro Gl - #y Lys Gly Pro Trp Gln            #     40                                                                       - GTG GCC TTC ATT GGG ATC ACC ACG GGC CTC CT - #G TCG CTA GCC ACA GTG           555                                                                           Val Ala Phe Ile Gly Ile Thr Thr Gly Leu Le - #u Ser Leu Ala Thr Val            # 60                                                                           - ACA GGC AAC CTG CTG GTA CTC ATC TCT TTC AA - #G GTC AAC ACG GAG CTC           603                                                                           Thr Gly Asn Leu Leu Val Leu Ile Ser Phe Ly - #s Val Asn Thr Glu Leu            #                 75                                                           - AAG ACA GTC AAT AAC TAC TTC CTG CTG AGC CT - #G GCC TGT GCT GAC CTC           651                                                                           Lys Thr Val Asn Asn Tyr Phe Leu Leu Ser Le - #u Ala Cys Ala Asp Leu            #             90                                                               - ATC ATC GGT ACC TTC TCC ATG AAC CTC TAT AC - #C ACG TAC CTG CTC ATG           699                                                                           Ile Ile Gly Thr Phe Ser Met Asn Leu Tyr Th - #r Thr Tyr Leu Leu Met            #        105                                                                   - GGC CAC TGG GCT CTG GGC ACG CTG GCT TGT GA - #C CTC TGG CTG GCC CTG           747                                                                           Gly His Trp Ala Leu Gly Thr Leu Ala Cys As - #p Leu Trp Leu Ala Leu            #   120                                                                        - GAC TAT GTG GCC AGC AAT GCC TCC GTC ATG AA - #T CTG CTG CTC ATC AGC           795                                                                           Asp Tyr Val Ala Ser Asn Ala Ser Val Met As - #n Leu Leu Leu Ile Ser            125                 1 - #30                 1 - #35                 1 -        #40                                                                            - TTT GAC CGC TAC TTC TCC GTG ACT CGG CCC CT - #G AGC TAC CGT GCC AAG           843                                                                           Phe Asp Arg Tyr Phe Ser Val Thr Arg Pro Le - #u Ser Tyr Arg Ala Lys            #               155                                                            - CGC ACA CCC CGC CGC GCA GCT CTG ATG ATC GG - #C CTG GCC TGG CTG GTT           891                                                                           Arg Thr Pro Arg Arg Ala Ala Leu Met Ile Gl - #y Leu Ala Trp Leu Val            #           170                                                                - TCC TTT GTG CTC TGG GCC CCA GCC ATC CTC TT - #C TGG CAA TAC CTG GTA           939                                                                           Ser Phe Val Leu Trp Ala Pro Ala Ile Leu Ph - #e Trp Gln Tyr Leu Val            #       185                                                                    - GGG GAG CGG ACG ATG CTA GCT GGG CAG TGC TA - #C ATC CAG TTC CTC TCC           987                                                                           Gly Glu Arg Thr Met Leu Ala Gly Gln Cys Ty - #r Ile Gln Phe Leu Ser            #   200                                                                        - CAG CCC ATC ATC ACC TTT GGC ACA GCC ATG GC - #T GCC TTC TAC CTC CCT          1035                                                                           Gln Pro Ile Ile Thr Phe Gly Thr Ala Met Al - #a Ala Phe Tyr Leu Pro            205                 2 - #10                 2 - #15                 2 -        #20                                                                            - GTC ACA GTC ATG TGC ACG CTC TAC TGG CGC AT - #C TAC CGG GAG ACA GAG          1083                                                                           Val Thr Val Met Cys Thr Leu Tyr Trp Arg Il - #e Tyr Arg Glu Thr Glu            #               235                                                            - AAC CGA GCA CGG GAG CTG GCA GCC CTT CAG GG - #C TCC GAG ACG CCA GGC          1131                                                                           Asn Arg Ala Arg Glu Leu Ala Ala Leu Gln Gl - #y Ser Glu Thr Pro Gly            #           250                                                                - AAA AAG GAG AAG AAG GCG GCT CGG ACC CTG AG - #T GCC ATC CTC CTG GCC          1179                                                                           Lys Lys Glu Lys Lys Ala Ala Arg Thr Leu Se - #r Ala Ile Leu Leu Ala            #       265                                                                    - TTC ATC CTC ACC TGG ACA CCG TAC AAC ATC AT - #G GTG CTG GTG TCC ACC          1227                                                                           Phe Ile Leu Thr Trp Thr Pro Tyr Asn Ile Me - #t Val Leu Val Ser Thr            #   280                                                                        - TTC TGC AAG GAC TGT GTT CCC GAG ACC CTG TG - #G GAG CTG GGC TAC TGG          1275                                                                           Phe Cys Lys Asp Cys Val Pro Glu Thr Leu Tr - #p Glu Leu Gly Tyr Trp            285                 2 - #90                 2 - #95                 3 -        #00                                                                            - CTG TGC TAC GTC AAC AGC ACC ATC AAC CCC AT - #G TGC TAC GCA CTC TGC          1323                                                                           Leu Cys Tyr Val Asn Ser Thr Ile Asn Pro Me - #t Cys Tyr Ala Leu Cys            #               315                                                            - AAC AAA GCC TTC CGG GAC ACC TTT CGC CTG CT - #G CTT TGC CGC TGG GAC          1371                                                                           Asn Lys Ala Phe Arg Asp Thr Phe Arg Leu Le - #u Leu Cys Arg Trp Asp            #           330                                                                - AAG AGA CGC TGG CGC AAG ATC CCC AAG CGC CC - #T GGC TCC GTG CAC CGC          1419                                                                           Lys Arg Arg Trp Arg Lys Ile Pro Lys Arg Pr - #o Gly Ser Val His Arg            #       345                                                                    - ACT CCC TCC CGC CAA TGC TGATAGTCCC CTCTCCTGCA TC - #CCTCCACC                 1467                                                                           Thr Pro Ser Arg Gln Cys                                                            350                                                                        - CCAGCGGCCG CGACCAGCGA TTGATCGCAC ACGCAGGACA GCCCCACAAC CG - #GCGCGGCT        1527                                                                           - GTGTTCAACG ACACACGATG AGTCCCCCAC TCGGTCTTGT ACTCGGATCC TT - #TT              1581                                                                           - (2) INFORMATION FOR SEQ ID NO:9:                                             -      (i) SEQUENCE CHARACTERISTICS:                                           #acids    (A) LENGTH: 354 amino                                                          (B) TYPE: amino acid                                                           (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: protein                                              -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:9:                                  - Met Leu Glu Leu Leu Pro Thr Ala Val Glu Gl - #y Val Ser Gln Ala Gln          #                 15                                                           - Ile Gln Ala Leu Met Asn Thr Ser Ala Pro Pr - #o Ala Val Ser Pro Asn          #             30                                                               - Ile Thr Val Leu Ala Pro Gly Lys Gly Pro Tr - #p Gln Val Ala Phe Ile          #         45                                                                   - Gly Ile Thr Thr Gly Leu Leu Ser Leu Ala Th - #r Val Thr Gly Asn Leu          #     60                                                                       - Leu Val Leu Ile Ser Phe Lys Val Asn Thr Gl - #u Leu Lys Thr Val Asn          # 80                                                                           - Asn Tyr Phe Leu Leu Ser Leu Ala Cys Ala As - #p Leu Ile Ile Gly Thr          #                 95                                                           - Phe Ser Met Asn Leu Tyr Thr Thr Tyr Leu Le - #u Met Gly His Trp Ala          #           110                                                                - Leu Gly Thr Leu Ala Cys Asp Leu Trp Leu Al - #a Leu Asp Tyr Val Ala          #       125                                                                    - Ser Asn Ala Ser Val Met Asn Leu Leu Leu Il - #e Ser Phe Asp Arg Tyr          #   140                                                                        - Phe Ser Val Thr Arg Pro Leu Ser Tyr Arg Al - #a Lys Arg Thr Pro Arg          145                 1 - #50                 1 - #55                 1 -        #60                                                                            - Arg Ala Ala Leu Met Ile Gly Leu Ala Trp Le - #u Val Ser Phe Val Leu          #               175                                                            - Trp Ala Pro Ala Ile Leu Phe Trp Gln Tyr Le - #u Val Gly Glu Arg Thr          #           190                                                                - Met Leu Ala Gly Gln Cys Tyr Ile Gln Phe Le - #u Ser Gln Pro Ile Ile          #       205                                                                    - Thr Phe Gly Thr Ala Met Ala Ala Phe Tyr Le - #u Pro Val Thr Val Met          #   220                                                                        - Cys Thr Leu Tyr Trp Arg Ile Tyr Arg Glu Th - #r Glu Asn Arg Ala Arg          225                 2 - #30                 2 - #35                 2 -        #40                                                                            - Glu Leu Ala Ala Leu Gln Gly Ser Glu Thr Pr - #o Gly Lys Lys Glu Lys          #               255                                                            - Lys Ala Ala Arg Thr Leu Ser Ala Ile Leu Le - #u Ala Phe Ile Leu Thr          #           270                                                                - Trp Thr Pro Tyr Asn Ile Met Val Leu Val Se - #r Thr Phe Cys Lys Asp          #       285                                                                    - Cys Val Pro Glu Thr Leu Trp Glu Leu Gly Ty - #r Trp Leu Cys Tyr Val          #   300                                                                        - Asn Ser Thr Ile Asn Pro Met Cys Tyr Ala Le - #u Cys Asn Lys Ala Phe          305                 3 - #10                 3 - #15                 3 -        #20                                                                            - Arg Asp Thr Phe Arg Leu Leu Leu Cys Arg Tr - #p Asp Lys Arg Arg Trp          #               335                                                            - Arg Lys Ile Pro Lys Arg Pro Gly Ser Val Hi - #s Arg Thr Pro Ser Arg          #           350                                                                - Gln Cys                                                                      - (2) INFORMATION FOR SEQ ID NO:10:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 1848 base                                                          (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: cDNA                                                 -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 376..414                                               #/note= "BacteriorhodopsinATION:                                                              pre-sequence - #."                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: terminator                                                       (B) LOCATION: 1756..1758                                             #/note= "Bacteriorhodopsin stop:                                                              codon."                                                         -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 517..591                                               #/note= "Helix I of rat serotonin                                              #protein (Type 1C)."tor                                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 625..690                                               #/note= "Helix II of rat serotonin                                             #protein (Type 1C)."tor                                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 736..807                                               #/note= "Helix III of rat serotonin                                            #protein (Type 1C)."tor                                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 868..939                                               #/note= "Helix IV of rat serotonin                                             #protein (Type 1C)."tor                                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 997..1059                                              #/note= "Helix V of rat serotonin                                              #protein (Type 1C)."tor                                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1297..1362                                             #/note= "Helix VI of rat serotonin                                             #protein (Type 1C)."tor                                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1411..1476                                             #/note= "Helix VII of rat serotonin                                            #protein (Type 1C)."tor                                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(213, - # "")                                   #/note= "G to A mutation removes                                                              AlwNI res - #triction site."                                    -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1732..1734                                             #/note= "Codon encoding theTION:                                               #amino acid of the rat serotonin                                               #protein (Type 1C)."tor                                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #signal                                            (B) LOCATION: 374                                                    #/note= "RNA start site."MATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: CDS                                                              (B) LOCATION: 376..1734                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: terminator                                                       (B) LOCATION: 1735..1737                                             #/note= "Serotonin stop codon.":                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: repeat.sub.-- - #region                                          (B) LOCATION: 436..462                                               #/note= "Sequence encodingATION:                                                              polyaspartic - # acid."                                         -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(1755 - #, "")                                  #/note= "C to T mutation removes                                                              AlwNI res - #triction site."                                    -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:10:                                 - ATCTGCAGGA TGGGTGCAAC CGTGAAGTCC GTCACGGCTG CGTCACGACA GG - #AGCCGACC          60                                                                           - AGCGACACCC AGAAGGTGCG AACGGTTGAG TGCCGCAACG ATCACGAGTT TT - #TCGTGCGC         120                                                                           - TTCGAGTGGT AACACGCGTG CACGCATCGA CTTCACCGCG GGTGTTTCGA CG - #CCAGCCGG         180                                                                           - CCGTTGAACC AGCAGGCAGC GGGCATTTCA CATCCGCTGT GGCCCACACA CT - #CGGTGGGG         240                                                                           - TGCGCTATTT TGGTATGGTT TGGAATCCGC GTGTCGGCTC CGTGTCTGAC GG - #TTCATCGG         300                                                                           - TCTAAATTCC GTCACGAGCG TACCATACTG ATTGGGTCGT AGAGTTACAC AC - #ATATCCTC         360                                                                           #GCA GTG GAG GGG GTA     411AG TTA TTG CCA ACA                                 #Leu Glu Leu Leu Pro Thr Ala Val Glu Gly V - #al                               #                10                                                            - TCG CAG GCC CAG ATC CAG GCG CTG GAC TAC AA - #G GAC GAT GAT GAC GTC           459                                                                           Ser Gln Ala Gln Ile Gln Ala Leu Asp Tyr Ly - #s Asp Asp Asp Asp Val            #         25                                                                   - GAC ACT TTT AAT TCC TCC GAT GGT GGA CGC TT - #G TTT CAA TTC CCG GAC           507                                                                           Asp Thr Phe Asn Ser Ser Asp Gly Gly Arg Le - #u Phe Gln Phe Pro Asp            #     40                                                                       - GGG GTA CAA AAC TGG CCA GCA CTT TCA ATC GT - #C GTG ATT ATA ATC ATG           555                                                                           Gly Val Gln Asn Trp Pro Ala Leu Ser Ile Va - #l Val Ile Ile Ile Met            # 60                                                                           - ACA ATA GGG GGC AAC ATT CTT GTT ATC ATG GC - #A GTA AGC ATG GAG AAG           603                                                                           Thr Ile Gly Gly Asn Ile Leu Val Ile Met Al - #a Val Ser Met Glu Lys            #                 75                                                           - AAA CTG CAC AAT GCA ACC AAT TAC TTC TTA AT - #G TCC CTA GCC ATT GCT           651                                                                           Lys Leu His Asn Ala Thr Asn Tyr Phe Leu Me - #t Ser Leu Ala Ile Ala            #             90                                                               - GAT ATG CTG GTG GGA CTA CTT GTC ATG CCC CT - #G TCC CTG CTT GCT ATT           699                                                                           Asp Met Leu Val Gly Leu Leu Val Met Pro Le - #u Ser Leu Leu Ala Ile            #        105                                                                   - CTT TAT GAT TAT GTC TGG CCT TTA CCT AGA TA - #T TTG TGC CCC GTC TGG           747                                                                           Leu Tyr Asp Tyr Val Trp Pro Leu Pro Arg Ty - #r Leu Cys Pro Val Trp            #   120                                                                        - ATT TCA CTA GAT GTG CTA TTT TCA ACT GCG TC - #C ATC ATG CAC CTC TGC           795                                                                           Ile Ser Leu Asp Val Leu Phe Ser Thr Ala Se - #r Ile Met His Leu Cys            125                 1 - #30                 1 - #35                 1 -        #40                                                                            - GCC ATA TCG CTG GAC CGG TAT GTA GCA ATA CG - #T AAT CCT ATT GAG CAT           843                                                                           Ala Ile Ser Leu Asp Arg Tyr Val Ala Ile Ar - #g Asn Pro Ile Glu His            #               155                                                            - AGC CGG TTC AAT TCG CGG ACT AAG GCC ATC AT - #G AAG ATT GCC ATC GTT           891                                                                           Ser Arg Phe Asn Ser Arg Thr Lys Ala Ile Me - #t Lys Ile Ala Ile Val            #           170                                                                - TGG GCA ATA TCA ATA GGA GTT TCA GTT CCT AT - #C CCT GTG ATT GGA CTG           939                                                                           Trp Ala Ile Ser Ile Gly Val Ser Val Pro Il - #e Pro Val Ile Gly Leu            #       185                                                                    - AGG GAC GAA AGC AAA GTG TTC GTG AAT AAC AC - #C ACG TGC GTG CTC AAT           987                                                                           Arg Asp Glu Ser Lys Val Phe Val Asn Asn Th - #r Thr Cys Val Leu Asn            #   200                                                                        - GAC CCC AAC TTC GTT CTC ATC GGG TCC TTC GT - #G GCA TTC TTC ATC CCG          1035                                                                           Asp Pro Asn Phe Val Leu Ile Gly Ser Phe Va - #l Ala Phe Phe Ile Pro            205                 2 - #10                 2 - #15                 2 -        #20                                                                            - TTG ACG ATT ATG GTG ATC ACC TAC TTC TTA AC - #G ATC TAC GTC CTG CGC          1083                                                                           Leu Thr Ile Met Val Ile Thr Tyr Phe Leu Th - #r Ile Tyr Val Leu Arg            #               235                                                            - CGT CAA ACT CTG ATG TTA CTT CGA GGT CAC AC - #C GAG GAG GAA CTG GCT          1131                                                                           Arg Gln Thr Leu Met Leu Leu Arg Gly His Th - #r Glu Glu Glu Leu Ala            #           250                                                                - AAT ATG AGC CTG AAC TTT CTG AAC TGC TGC TG - #C AAG AAG AAT GGT GGT          1179                                                                           Asn Met Ser Leu Asn Phe Leu Asn Cys Cys Cy - #s Lys Lys Asn Gly Gly            #       265                                                                    - GAG GAA GAG AAC GCT CCG AAC CCT AAT CCA GA - #T CAG AAA CCA CGT CGA          1227                                                                           Glu Glu Glu Asn Ala Pro Asn Pro Asn Pro As - #p Gln Lys Pro Arg Arg            #   280                                                                        - AAG AAG AAA GAA AAG CGT CCC AGA GGC ACC AT - #G CAA GCT ATC AAC AAC          1275                                                                           Lys Lys Lys Glu Lys Arg Pro Arg Gly Thr Me - #t Gln Ala Ile Asn Asn            285                 2 - #90                 2 - #95                 3 -        #00                                                                            - GAA AAG AAA GCT TCC AAA GTC CTT GGC ATT GT - #A TTC TTT GTG TTT CTG          1323                                                                           Glu Lys Lys Ala Ser Lys Val Leu Gly Ile Va - #l Phe Phe Val Phe Leu            #               315                                                            - ATC ATG TGG TGC CCG TTT TTC ATC ACC AAT AT - #C CTG TCG GTT CTT TGT          1371                                                                           Ile Met Trp Cys Pro Phe Phe Ile Thr Asn Il - #e Leu Ser Val Leu Cys            #           330                                                                - GGG AAG GCC TGT AAC CAA AAG CTA ATG GAG AA - #G CTT CTC AAT GTG TTT          1419                                                                           Gly Lys Ala Cys Asn Gln Lys Leu Met Glu Ly - #s Leu Leu Asn Val Phe            #       345                                                                    - GTG TGG ATT GGC TAT GTG TGT TCA GGC ATC AA - #T CCT CTG GTG TAC ACT          1467                                                                           Val Trp Ile Gly Tyr Val Cys Ser Gly Ile As - #n Pro Leu Val Tyr Thr            #   360                                                                        - CTC TTT AAT AAA ATT TAC CGA AGG GCT TTC TC - #T AAA TAT TTG CGC TGC          1515                                                                           Leu Phe Asn Lys Ile Tyr Arg Arg Ala Phe Se - #r Lys Tyr Leu Arg Cys            365                 3 - #70                 3 - #75                 3 -        #80                                                                            - GAT TAT AAG CCA GAC AAA AAG CCT CCT GTT CG - #A CAG ATT CCT AGG GTT          1563                                                                           Asp Tyr Lys Pro Asp Lys Lys Pro Pro Val Ar - #g Gln Ile Pro Arg Val            #               395                                                            - GCT GCC ACT GCT TTG TCT GGG AGG GAG CTC AA - #T GTT AAC ATT TAT CGG          1611                                                                           Ala Ala Thr Ala Leu Ser Gly Arg Glu Leu As - #n Val Asn Ile Tyr Arg            #           410                                                                - CAT ACC AAT GAA CGT GTG GCT AGG AAA GCT AA - #T GAC CCT GAG CCT GGC          1659                                                                           His Thr Asn Glu Arg Val Ala Arg Lys Ala As - #n Asp Pro Glu Pro Gly            #       425                                                                    - ATA GAG ATG CAG GTG GAG AAC TTA GAG CTG CC - #A GTC AAC CCC TCT AAT          1707                                                                           Ile Glu Met Gln Val Glu Asn Leu Glu Leu Pr - #o Val Asn Pro Ser Asn            #   440                                                                        - GTG GTC AGC GAG AGG ATT AGT AGT GTG TGAGCGGCC - #G CGACCAGCGA                1754                                                                           Val Val Ser Glu Arg Ile Ser Ser Val                                            445                 4 - #50                                                    - TTGATCGCAC ACGCAGGACA GCCCCACAAC CGGCGCGGCT GTGTTCAACG AC - #ACACGATG        1814                                                                           #      1848        TTGT ACTCGGATCC TTTT                                        - (2) INFORMATION FOR SEQ ID NO:11:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #acids    (A) LENGTH: 453 amino                                                          (B) TYPE: amino acid                                                           (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: protein                                              -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:11:                                 - Met Leu Glu Leu Leu Pro Thr Ala Val Glu Gl - #y Val Ser Gln Ala Gln          #                 15                                                           - Ile Gln Ala Leu Asp Tyr Lys Asp Asp Asp As - #p Val Asp Thr Phe Asn          #             30                                                               - Ser Ser Asp Gly Gly Arg Leu Phe Gln Phe Pr - #o Asp Gly Val Gln Asn          #         45                                                                   - Trp Pro Ala Leu Ser Ile Val Val Ile Ile Il - #e Met Thr Ile Gly Gly          #     60                                                                       - Asn Ile Leu Val Ile Met Ala Val Ser Met Gl - #u Lys Lys Leu His Asn          # 80                                                                           - Ala Thr Asn Tyr Phe Leu Met Ser Leu Ala Il - #e Ala Asp Met Leu Val          #                 95                                                           - Gly Leu Leu Val Met Pro Leu Ser Leu Leu Al - #a Ile Leu Tyr Asp Tyr          #           110                                                                - Val Trp Pro Leu Pro Arg Tyr Leu Cys Pro Va - #l Trp Ile Ser Leu Asp          #       125                                                                    - Val Leu Phe Ser Thr Ala Ser Ile Met His Le - #u Cys Ala Ile Ser Leu          #   140                                                                        - Asp Arg Tyr Val Ala Ile Arg Asn Pro Ile Gl - #u His Ser Arg Phe Asn          145                 1 - #50                 1 - #55                 1 -        #60                                                                            - Ser Arg Thr Lys Ala Ile Met Lys Ile Ala Il - #e Val Trp Ala Ile Ser          #               175                                                            - Ile Gly Val Ser Val Pro Ile Pro Val Ile Gl - #y Leu Arg Asp Glu Ser          #           190                                                                - Lys Val Phe Val Asn Asn Thr Thr Cys Val Le - #u Asn Asp Pro Asn Phe          #       205                                                                    - Val Leu Ile Gly Ser Phe Val Ala Phe Phe Il - #e Pro Leu Thr Ile Met          #   220                                                                        - Val Ile Thr Tyr Phe Leu Thr Ile Tyr Val Le - #u Arg Arg Gln Thr Leu          225                 2 - #30                 2 - #35                 2 -        #40                                                                            - Met Leu Leu Arg Gly His Thr Glu Glu Glu Le - #u Ala Asn Met Ser Leu          #               255                                                            - Asn Phe Leu Asn Cys Cys Cys Lys Lys Asn Gl - #y Gly Glu Glu Glu Asn          #           270                                                                - Ala Pro Asn Pro Asn Pro Asp Gln Lys Pro Ar - #g Arg Lys Lys Lys Glu          #       285                                                                    - Lys Arg Pro Arg Gly Thr Met Gln Ala Ile As - #n Asn Glu Lys Lys Ala          #   300                                                                        - Ser Lys Val Leu Gly Ile Val Phe Phe Val Ph - #e Leu Ile Met Trp Cys          305                 3 - #10                 3 - #15                 3 -        #20                                                                            - Pro Phe Phe Ile Thr Asn Ile Leu Ser Val Le - #u Cys Gly Lys Ala Cys          #               335                                                            - Asn Gln Lys Leu Met Glu Lys Leu Leu Asn Va - #l Phe Val Trp Ile Gly          #           350                                                                - Tyr Val Cys Ser Gly Ile Asn Pro Leu Val Ty - #r Thr Leu Phe Asn Lys          #       365                                                                    - Ile Tyr Arg Arg Ala Phe Ser Lys Tyr Leu Ar - #g Cys Asp Tyr Lys Pro          #   380                                                                        - Asp Lys Lys Pro Pro Val Arg Gln Ile Pro Ar - #g Val Ala Ala Thr Ala          385                 3 - #90                 3 - #95                 4 -        #00                                                                            - Leu Ser Gly Arg Glu Leu Asn Val Asn Ile Ty - #r Arg His Thr Asn Glu          #               415                                                            - Arg Val Ala Arg Lys Ala Asn Asp Pro Glu Pr - #o Gly Ile Glu Met Gln          #           430                                                                - Val Glu Asn Leu Glu Leu Pro Val Asn Pro Se - #r Asn Val Val Ser Glu          #       445                                                                    - Arg Ile Ser Ser Val                                                              450                                                                        - (2) INFORMATION FOR SEQ ID NO:12:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 1764 base                                                          (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: cDNA                                                 -     (ix) FEATURE:                                                                      (A) NAME/KEY: repeat.sub.-- - #region                                          (B) LOCATION: 436..462                                               #/note= "Sequence encodingATION:                                                              polyaspartic - # acid."                                         -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 463..465                                               #/note= "Codon encoding theTION:                                               #amino acid of the human thrombin                                              #protein."     receptor                                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1630..1632                                             #/note= "Codon encoding theTION:                                               #amino acid of the human thrombin                                              #protein. "    receptor                                                        -     (ix) FEATURE:                                                                      (A) NAME/KEY: repeat.sub.-- - #region                                          (B) LOCATION: 1633..1650                                             #/note= "Sequence encodingATION:                                                              polyhistidin - #e."                                             -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 648..656                                               #/note= "Deleted AlwNI restriction                                                            site."                                                          -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 893..898                                               #/note= "Deleted PstI restriction                                                             site."                                                          -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1301..1309                                             #/note= "Deleted AlwNI restriction                                                            site."                                                          -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1394..1402                                             #/note= "Deleted AlwNI restriction                                                            site."                                                          -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #signal                                            (B) LOCATION: 374                                                    #/note= "RNA start site."MATION:                                               -     (ix) FEATURE:                                                                      (A) NAME/KEY: mutation                                                         (B) LOCATION: replace(1671 - #, "")                                  #/note= "C to T mutation removes                                                              AlwNI sit - #e."                                                -     (ix) FEATURE:                                                                      (A) NAME/KEY: CDS                                                              (B) LOCATION: 376..1650                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 376..414                                               #/note= "BacteriorhodopsinATION:                                                              pre-sequence - #."                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: terminator                                                       (B) LOCATION: 1672..1674                                             #/note= "Bacteriorhodopsin stop:                                                              codon."                                                         -     (ix) FEATURE:                                                                      (A) NAME/KEY: terminator                                                       (B) LOCATION: 1651..1653                                             #/note= "Thrombin stop codon."N:                                               -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:12:                                 - ATCTGCAGGA TGGGTGCAAC CGTGAAGTCC GTCACGGCTG CGTCACGACA GG - #AGCCGACC          60                                                                           - AGCGACACCC AGAAGGTGCG AACGGTTGAG TGCCGCAACG ATCACGAGTT TT - #TCGTGCGC         120                                                                           - TTCGAGTGGT AACACGCGTG CACGCATCGA CTTCACCGCG GGTGTTTCGA CG - #CCAGCCGG         180                                                                           - CCGTTGAACC AGCAGGCAGC GGGCATTTCA CATCCGCTGT GGCCCACACA CT - #CGGTGGGG         240                                                                           - TGCGCTATTT TGGTATGGTT TGGAATCCGC GTGTCGGCTC CGTGTCTGAC GG - #TTCATCGG         300                                                                           - TCTAAATTCC GTCACGAGCG TACCATACTG ATTGGGTCGT AGAGTTACAC AC - #ATATCCTC         360                                                                           #GCA GTG GAG GGG GTA     411AG TTA TTG CCA ACA                                 #Leu Glu Leu Leu Pro Thr Ala Val Glu Gly V - #al                               #                10                                                            - TCG CAG GCC CAG ATC CAG GCG CTG GAC TAC AA - #G GAC GAT GAT GAC GTC           459                                                                           Ser Gln Ala Gln Ile Gln Ala Leu Asp Tyr Ly - #s Asp Asp Asp Asp Val            #         25                                                                   - GAC GCC ACC TTA GAT CCC CGG TCA TTT CTT CT - #C AGG AAC CCC AAT GAT           507                                                                           Asp Ala Thr Leu Asp Pro Arg Ser Phe Leu Le - #u Arg Asn Pro Asn Asp            #     40                                                                       - AAA TAT GAA CCA TTT TGG GAG GAT GAG GAG AA - #A AAT GAA AGT GGG TTA           555                                                                           Lys Tyr Glu Pro Phe Trp Glu Asp Glu Glu Ly - #s Asn Glu Ser Gly Leu            # 60                                                                           - ACT GAA TAC AGA TTA GTC TCC ATC AAT AAA AG - #C AGT CCT CTT CAA AAA           603                                                                           Thr Glu Tyr Arg Leu Val Ser Ile Asn Lys Se - #r Ser Pro Leu Gln Lys            #                 75                                                           - CAA CTT CCT GCA TTC ATC TCA GAA GAT GCC TC - #C GGA TAT TTG ACC AGC           651                                                                           Gln Leu Pro Ala Phe Ile Ser Glu Asp Ala Se - #r Gly Tyr Leu Thr Ser            #             90                                                               - TCC TGG CTG ACA CTC TTT GTC CCA TCT GTG TA - #C ACC GGA GTG TTT GTA           699                                                                           Ser Trp Leu Thr Leu Phe Val Pro Ser Val Ty - #r Thr Gly Val Phe Val            #        105                                                                   - GTC AGC CTC CCA CTA AAC ATC ATG GCC ATC GT - #T GTG TTC ATC CTG AAA           747                                                                           Val Ser Leu Pro Leu Asn Ile Met Ala Ile Va - #l Val Phe Ile Leu Lys            #   120                                                                        - ATG AAG GTC AAG AAG CCG GCG GTG GTG TAC AT - #G CTG CAC CTG GCC ACG           795                                                                           Met Lys Val Lys Lys Pro Ala Val Val Tyr Me - #t Leu His Leu Ala Thr            125                 1 - #30                 1 - #35                 1 -        #40                                                                            - GCA GAT GTG CTG TTT GTG TCT GTG CTC CCC TT - #T AAG ATC AGC TAT TAC           843                                                                           Ala Asp Val Leu Phe Val Ser Val Leu Pro Ph - #e Lys Ile Ser Tyr Tyr            #               155                                                            - TTT TCC GGC AGT GAT TGG CAG TTT GGG TCT GA - #A TTG TGT CGC TTC GTC           891                                                                           Phe Ser Gly Ser Asp Trp Gln Phe Gly Ser Gl - #u Leu Cys Arg Phe Val            #           170                                                                - ACT GCA GCA TTT TAC TGT AAC ATG TAC GCC TC - #T ATC TTG CTC ATG ACA           939                                                                           Thr Ala Ala Phe Tyr Cys Asn Met Tyr Ala Se - #r Ile Leu Leu Met Thr            #       185                                                                    - GTC ATA AGC ATT GAC CGG TTT CTG GCT GTG GT - #G TAT CCC ATG CAG TCC           987                                                                           Val Ile Ser Ile Asp Arg Phe Leu Ala Val Va - #l Tyr Pro Met Gln Ser            #   200                                                                        - CTC TCC TGG CGT ACT CTG GGA AGG GCT TCC TT - #C ACT TGT CTG GCC ATC          1035                                                                           Leu Ser Trp Arg Thr Leu Gly Arg Ala Ser Ph - #e Thr Cys Leu Ala Ile            205                 2 - #10                 2 - #15                 2 -        #20                                                                            - TGG GCT TTG GCC ATC GCA GGG GTA GTG CCT CT - #C GTC CTC AAG GAG CAA          1083                                                                           Trp Ala Leu Ala Ile Ala Gly Val Val Pro Le - #u Val Leu Lys Glu Gln            #               235                                                            - ACC ATC CAG GTG CCC GGG CTC AAC ATC ACT AC - #C TGT CAT GAT GTG CTC          1131                                                                           Thr Ile Gln Val Pro Gly Leu Asn Ile Thr Th - #r Cys His Asp Val Leu            #           250                                                                - AAT GAA ACC CTG CTC GAA GGC TAC TAT GCC TA - #C TAC TTC TCA GCC TTC          1179                                                                           Asn Glu Thr Leu Leu Glu Gly Tyr Tyr Ala Ty - #r Tyr Phe Ser Ala Phe            #       265                                                                    - TCT GCT GTC TTC TTT TTT GTG CCG CTG ATC AT - #T TCC ACG GTC TGT TAT          1227                                                                           Ser Ala Val Phe Phe Phe Val Pro Leu Ile Il - #e Ser Thr Val Cys Tyr            #   280                                                                        - GTG TCT ATC ATT CGA TGT CTT AGC TCT TCC GC - #A GTT GCC AAC CGC AGC          1275                                                                           Val Ser Ile Ile Arg Cys Leu Ser Ser Ser Al - #a Val Ala Asn Arg Ser            285                 2 - #90                 2 - #95                 3 -        #00                                                                            - AAG AAG TCC CGG GCT TTG TTC CTG TCA GCT GC - #T GTT TTC TGC ATC TTC          1323                                                                           Lys Lys Ser Arg Ala Leu Phe Leu Ser Ala Al - #a Val Phe Cys Ile Phe            #               315                                                            - ATC ATT TGC TTC GGA CCC ACA AAC GTC CTC CT - #G ATT GCG CAT TAC TCA          1371                                                                           Ile Ile Cys Phe Gly Pro Thr Asn Val Leu Le - #u Ile Ala His Tyr Ser            #           330                                                                - TTC CTT TCT CAC ACT TCC ACC ACA GAG GCT GC - #C TAC TTT GCC TAC CTC          1419                                                                           Phe Leu Ser His Thr Ser Thr Thr Glu Ala Al - #a Tyr Phe Ala Tyr Leu            #       345                                                                    - CTC TGT GTC TGT GTC AGC AGC ATA AGC TCG TG - #C ATC GAC CCC CTA ATT          1467                                                                           Leu Cys Val Cys Val Ser Ser Ile Ser Ser Cy - #s Ile Asp Pro Leu Ile            #   360                                                                        - TAC TAT TAC GCT TCC TCT GAG TGC CAG AGG TA - #C GTC TAC AGT ATC TTA          1515                                                                           Tyr Tyr Tyr Ala Ser Ser Glu Cys Gln Arg Ty - #r Val Tyr Ser Ile Leu            365                 3 - #70                 3 - #75                 3 -        #80                                                                            - TGC TGC AAA GAA AGT TCC GAT CCC AGC AGT TA - #T AAC AGC AGT GGG CAG          1563                                                                           Cys Cys Lys Glu Ser Ser Asp Pro Ser Ser Ty - #r Asn Ser Ser Gly Gln            #               395                                                            - TTG ATG GCA AGT AAA ATG GAT ACC TGC TCT AG - #T AAC CTG AAT AAC AGC          1611                                                                           Leu Met Ala Ser Lys Met Asp Thr Cys Ser Se - #r Asn Leu Asn Asn Ser            #           410                                                                - ATA TAC AAA AAG CTG TTA ACT CAC CAC CAC CA - #C CAC CAC TGAGCGGCCG           1660                                                                           Ile Tyr Lys Lys Leu Leu Thr His His His Hi - #s His His                        #       425                                                                    - CGACCAGCGA TTGATCGCAC ACGCAGGACA GCCCCACAAC CGGCGCGGCT GT - #GTTCAACG        1720                                                                           #                 176 - #4GGTCTTGT ACTCGGATCC TTTT                             - (2) INFORMATION FOR SEQ ID NO:13:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #acids    (A) LENGTH: 425 amino                                                          (B) TYPE: amino acid                                                           (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: protein                                              -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:13:                                 - Met Leu Glu Leu Leu Pro Thr Ala Val Glu Gl - #y Val Ser Gln Ala Gln          #                 15                                                           - Ile Gln Ala Leu Asp Tyr Lys Asp Asp Asp As - #p Val Asp Ala Thr Leu          #             30                                                               - Asp Pro Arg Ser Phe Leu Leu Arg Asn Pro As - #n Asp Lys Tyr Glu Pro          #         45                                                                   - Phe Trp Glu Asp Glu Glu Lys Asn Glu Ser Gl - #y Leu Thr Glu Tyr Arg          #     60                                                                       - Leu Val Ser Ile Asn Lys Ser Ser Pro Leu Gl - #n Lys Gln Leu Pro Ala          # 80                                                                           - Phe Ile Ser Glu Asp Ala Ser Gly Tyr Leu Th - #r Ser Ser Trp Leu Thr          #                 95                                                           - Leu Phe Val Pro Ser Val Tyr Thr Gly Val Ph - #e Val Val Ser Leu Pro          #           110                                                                - Leu Asn Ile Met Ala Ile Val Val Phe Ile Le - #u Lys Met Lys Val Lys          #       125                                                                    - Lys Pro Ala Val Val Tyr Met Leu His Leu Al - #a Thr Ala Asp Val Leu          #   140                                                                        - Phe Val Ser Val Leu Pro Phe Lys Ile Ser Ty - #r Tyr Phe Ser Gly Ser          145                 1 - #50                 1 - #55                 1 -        #60                                                                            - Asp Trp Gln Phe Gly Ser Glu Leu Cys Arg Ph - #e Val Thr Ala Ala Phe          #               175                                                            - Tyr Cys Asn Met Tyr Ala Ser Ile Leu Leu Me - #t Thr Val Ile Ser Ile          #           190                                                                - Asp Arg Phe Leu Ala Val Val Tyr Pro Met Gl - #n Ser Leu Ser Trp Arg          #       205                                                                    - Thr Leu Gly Arg Ala Ser Phe Thr Cys Leu Al - #a Ile Trp Ala Leu Ala          #   220                                                                        - Ile Ala Gly Val Val Pro Leu Val Leu Lys Gl - #u Gln Thr Ile Gln Val          225                 2 - #30                 2 - #35                 2 -        #40                                                                            - Pro Gly Leu Asn Ile Thr Thr Cys His Asp Va - #l Leu Asn Glu Thr Leu          #               255                                                            - Leu Glu Gly Tyr Tyr Ala Tyr Tyr Phe Ser Al - #a Phe Ser Ala Val Phe          #           270                                                                - Phe Phe Val Pro Leu Ile Ile Ser Thr Val Cy - #s Tyr Val Ser Ile Ile          #       285                                                                    - Arg Cys Leu Ser Ser Ser Ala Val Ala Asn Ar - #g Ser Lys Lys Ser Arg          #   300                                                                        - Ala Leu Phe Leu Ser Ala Ala Val Phe Cys Il - #e Phe Ile Ile Cys Phe          305                 3 - #10                 3 - #15                 3 -        #20                                                                            - Gly Pro Thr Asn Val Leu Leu Ile Ala His Ty - #r Ser Phe Leu Ser His          #               335                                                            - Thr Ser Thr Thr Glu Ala Ala Tyr Phe Ala Ty - #r Leu Leu Cys Val Cys          #           350                                                                - Val Ser Ser Ile Ser Ser Cys Ile Asp Pro Le - #u Ile Tyr Tyr Tyr Ala          #       365                                                                    - Ser Ser Glu Cys Gln Arg Tyr Val Tyr Ser Il - #e Leu Cys Cys Lys Glu          #   380                                                                        - Ser Ser Asp Pro Ser Ser Tyr Asn Ser Ser Gl - #y Gln Leu Met Ala Ser          385                 3 - #90                 3 - #95                 4 -        #00                                                                            - Lys Met Asp Thr Cys Ser Ser Asn Leu Asn As - #n Ser Ile Tyr Lys Lys          #               415                                                            - Leu Leu Thr His His His His His His                                          #           425                                                                - (2) INFORMATION FOR SEQ ID NO:14:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #pairs    (A) LENGTH: 2147 base                                                          (B) TYPE: nucleic acid                                                         (C) STRANDEDNESS: single                                                       (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: cDNA                                                 -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #signal                                            (B) LOCATION: 378..380                                               #/note= "Bacteriorhodopsin start                                                              codon."                                                         -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 378..416                                               #/note= "BacteriorhodopsinATION:                                                              pre-sequence - #."                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: CDS                                                              (B) LOCATION: 378..2054                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 417..419                                               #/note= "Codon encoding N-terminal                                                            amino aci - #d of mature bacteriorhodopsin."                    -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1122..1124                                             #/note= "Codon encoding amino acid                                                            number 23 - #6 of bacteriorhodopsin."                           -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1137..1139                                             #/note= "Codon encoding amino acid                                             #of the catalytic subunit of E. coli                                           #Transcarbamylase."rtate                                                       -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1125..1178                                             #/note= "Synthetic DNA fragment."                                              -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 1125..1136                                             #/note= "Sequence encoding Factor Xa                                           #site."        proteolytic                                                     -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 2037..2039                                             #/note= "Codon encoding amino acid                                                            number 30 - #6 of E. coli Aspartate Transcarbamylase."          -     (ix) FEATURE:                                                                      (A) NAME/KEY: misc.sub.-- - #feature                                           (B) LOCATION: 2040..2054                                             #/note= "Sequence encodingATION:                                                              bacteriorhod - #opsin C-terminal amino acid numbers                            245 throu - #gh 249. "                                          -     (ix) FEATURE:                                                                      (A) NAME/KEY: terminator                                                       (B) LOCATION: 2055..2057                                             #/note= "Bacteriorhodopsin stop:                                                              codon."                                                         -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:14:                                 - TAATCTGCAG GATGGGTGCA ACCGTGAAGT CCGTCACGGC TGCGTCACGA CA - #GGAGCCGA          60                                                                           - CCAGCGACAC CCAGAAGGTG CGAACGGTTG AGTGCCGCAA CGATCACGAG TT - #TTTCGTGC         120                                                                           - GCTTCGAGTG GTAACACGCG TGCACGCATC GACTTCACCG CGGGTGTTTC GA - #CGCCAGCC         180                                                                           - GGCCGTTGAA CCAGCAGGCA GCGGGCATTT CACAGCCGCT GTGGCCCACA CA - #CTCGGTGG         240                                                                           - GGTGCGCTAT TTTGGTATGG TTTGGAATCC GCGTGTCGGC TCCGTGTCTG AC - #GGTTCATC         300                                                                           - GGTCTAAATT CCGTCACGAG CGTACCATAC TGATTGGGTC GTAGAGTTAC AC - #ACATATCC         360                                                                           #GCA GTG GAG GGG       410TG GAG TTA TTG CCA ACA                               #Glyt Leu Glu Leu Leu Pro Thr Ala Val Glu                                      #10                                                                            - GTA TCG CAG GCC CAG ATC ACC GGA CGT CCG GA - #G TGG ATC TGG CTA GCG           458                                                                           Val Ser Gln Ala Gln Ile Thr Gly Arg Pro Gl - #u Trp Ile Trp Leu Ala            #             25                                                               - CTC GGT ACG GCG CTA ATG GGA CTC GGG ACG CT - #C TAT TTC CTC GTG AAA           506                                                                           Leu Gly Thr Ala Leu Met Gly Leu Gly Thr Le - #u Tyr Phe Leu Val Lys            #         40                                                                   - GGG ATG GGC GTC TCG GAC CCA GAT GCA AAG AA - #A TTC TAC GCC ATC ACG           554                                                                           Gly Met Gly Val Ser Asp Pro Asp Ala Lys Ly - #s Phe Tyr Ala Ile Thr            #     55                                                                       - ACG CTC GTC CCA GCC ATC GCG TTC ACG ATG TA - #C CTC TCG ATG CTG CTG           602                                                                           Thr Leu Val Pro Ala Ile Ala Phe Thr Met Ty - #r Leu Ser Met Leu Leu            # 75                                                                           - GGG TAT GGC CTC ACA ATG GTA CCG TTC GGT GG - #G GAG CAG AAC CCC ATC           650                                                                           Gly Tyr Gly Leu Thr Met Val Pro Phe Gly Gl - #y Glu Gln Asn Pro Ile            #                 90                                                           - TAC TGG GCG CGG TAC GCT GAC TGG CTG TTC AC - #C ACG CCG CTG TTG TTG           698                                                                           Tyr Trp Ala Arg Tyr Ala Asp Trp Leu Phe Th - #r Thr Pro Leu Leu Leu            #            105                                                               - TTA GAC CTC GCG TTG CTC GTT GAC GCG GAT CA - #G GGA ACG ATC CTT GCG           746                                                                           Leu Asp Leu Ala Leu Leu Val Asp Ala Asp Gl - #n Gly Thr Ile Leu Ala            #       120                                                                    - CTC GTC GGT GCC GAC GGC ATC ATG ATC GGG AC - #C GGC CTG GTC GGC GCA           794                                                                           Leu Val Gly Ala Asp Gly Ile Met Ile Gly Th - #r Gly Leu Val Gly Ala            #   135                                                                        - CTG ACG AAG GTC TAC TCG TAC CGC TTC GTG TG - #G TGG GCG ATC AGC ACC           842                                                                           Leu Thr Lys Val Tyr Ser Tyr Arg Phe Val Tr - #p Trp Ala Ile Ser Thr            140                 1 - #45                 1 - #50                 1 -        #55                                                                            - GCA GCG ATG CTG TAC ATC CTG TAC GTG CTG TT - #C TTC GGG TTC ACC TCG           890                                                                           Ala Ala Met Leu Tyr Ile Leu Tyr Val Leu Ph - #e Phe Gly Phe Thr Ser            #               170                                                            - AAG GCC GAA AGC ATG CGC CCC GAG GTC GCA TC - #C ACG TTC AAA GTA CTG           938                                                                           Lys Ala Glu Ser Met Arg Pro Glu Val Ala Se - #r Thr Phe Lys Val Leu            #           185                                                                - CGT AAC GTT ACC GTT GTG TTG TGG TCC GCG TA - #T CCC GTC GTG TGG CTG           986                                                                           Arg Asn Val Thr Val Val Leu Trp Ser Ala Ty - #r Pro Val Val Trp Leu            #       200                                                                    - ATC GGC AGC GAA GGT GCG GGA ATC GTG CCG CT - #G AAC ATC GAG ACG CTG          1034                                                                           Ile Gly Ser Glu Gly Ala Gly Ile Val Pro Le - #u Asn Ile Glu Thr Leu            #   215                                                                        - CTG TTC ATG GTG CTT GAC GTG AGC GCG AAG GT - #C GGC TTC GGG CTC ATC          1082                                                                           Leu Phe Met Val Leu Asp Val Ser Ala Lys Va - #l Gly Phe Gly Leu Ile            220                 2 - #25                 2 - #30                 2 -        #35                                                                            - CTC CTG CGC AGT CGT GCG ATC TTC GGC GAA GC - #C GAA GCG CCG ATC GAA          1130                                                                           Leu Leu Arg Ser Arg Ala Ile Phe Gly Glu Al - #a Glu Ala Pro Ile Glu            #               250                                                            - GGT CGT CAG AAA CAT ATC ATT TCC ATA AAC GA - #C CTT AGT CGC GAT GAC          1178                                                                           Gly Arg Gln Lys His Ile Ile Ser Ile Asn As - #p Leu Ser Arg Asp Asp            #           265                                                                - CTT AAT CTG GTG CTG GCG ACA GCG GCG AAA CT - #G AAA GCA AAC CCG CAA          1226                                                                           Leu Asn Leu Val Leu Ala Thr Ala Ala Lys Le - #u Lys Ala Asn Pro Gln            #       280                                                                    - CCA GAG CTG TTG AAG CAC AAA GTC ATT GCC AG - #C TGT TTC TTC GAA GCC          1274                                                                           Pro Glu Leu Leu Lys His Lys Val Ile Ala Se - #r Cys Phe Phe Glu Ala            #   295                                                                        - TCT ACC CGT ACC CGC CTC TCT TTT CAA ACA TC - #T ATG CAC CGC CTG GGG          1322                                                                           Ser Thr Arg Thr Arg Leu Ser Phe Gln Thr Se - #r Met His Arg Leu Gly            300                 3 - #05                 3 - #10                 3 -        #15                                                                            - GCC AGC GTG GTG GGC TTC TCC GAC AGC GCC AA - #T ACA TCA CTG GGT AAA          1370                                                                           Ala Ser Val Val Gly Phe Ser Asp Ser Ala As - #n Thr Ser Leu Gly Lys            #               330                                                            - AAA GGC GAA ACG CTT GCC GAT ACC ATT TCA GT - #T ATC AGC ACT TAC GTC          1418                                                                           Lys Gly Glu Thr Leu Ala Asp Thr Ile Ser Va - #l Ile Ser Thr Tyr Val            #           345                                                                - GAT GCG ATA GTG ATG CGT CAT CCG CAG GAA GG - #T GCG GCG CGC CTG GCC          1466                                                                           Asp Ala Ile Val Met Arg His Pro Gln Glu Gl - #y Ala Ala Arg Leu Ala            #       360                                                                    - ACC GAG TTT TCC GGC AAT GTA CCG GTA CTG AA - #T GCC GGT GAT GGC TCC          1514                                                                           Thr Glu Phe Ser Gly Asn Val Pro Val Leu As - #n Ala Gly Asp Gly Ser            #   375                                                                        - AAC CAA CAT CCG ACG CAA ACC TTG CTG GAC TT - #A TTC ACT ATT CAG GAA          1562                                                                           Asn Gln His Pro Thr Gln Thr Leu Leu Asp Le - #u Phe Thr Ile Gln Glu            380                 3 - #85                 3 - #90                 3 -        #95                                                                            - ACC CAG GGG CGT CTG GAC AAT CTC CAC GTC GC - #A ATG GTT GGT GAC CTG          1610                                                                           Thr Gln Gly Arg Leu Asp Asn Leu His Val Al - #a Met Val Gly Asp Leu            #               410                                                            - AAA TAT GGT CGC ACC GTT CAC TCC CTG ACT CA - #G GCG TTA GCT AAG TTC          1658                                                                           Lys Tyr Gly Arg Thr Val His Ser Leu Thr Gl - #n Ala Leu Ala Lys Phe            #           425                                                                - GAC GGC AAC CGT TTT TAC TTC ATC GCG CCG GA - #C GCG CTG GCA ATG CCG          1706                                                                           Asp Gly Asn Arg Phe Tyr Phe Ile Ala Pro As - #p Ala Leu Ala Met Pro            #       440                                                                    - CAA TAC ATT CTG GAT ATG CTC GAT GAA AAA GG - #G ATC GCA TGG AGT CTG          1754                                                                           Gln Tyr Ile Leu Asp Met Leu Asp Glu Lys Gl - #y Ile Ala Trp Ser Leu            #   455                                                                        - CAC AGC TCT ATT GAA GAA GTG ATG GTG GAA GT - #A GAC ATC CTG TAC ATG          1802                                                                           His Ser Ser Ile Glu Glu Val Met Val Glu Va - #l Asp Ile Leu Tyr Met            460                 4 - #65                 4 - #70                 4 -        #75                                                                            - ACC CGC GTG CAA AAA GAG CGT CTG GAC CCG TC - #C GAG TAC GCC AAC GTG          1850                                                                           Thr Arg Val Gln Lys Glu Arg Leu Asp Pro Se - #r Glu Tyr Ala Asn Val            #               490                                                            - AAA GCG CAG TTT GTT CTT CGC GCC AGT GAT CT - #C CAC AAC GCC AAA GCC          1898                                                                           Lys Ala Gln Phe Val Leu Arg Ala Ser Asp Le - #u His Asn Ala Lys Ala            #           505                                                                - AAT ATG AAA GTG CTG CAT CCG TTG CCG CGT GT - #T GAT GAG ATT GCG ACG          1946                                                                           Asn Met Lys Val Leu His Pro Leu Pro Arg Va - #l Asp Glu Ile Ala Thr            #       520                                                                    - GAT GTT GAT AAA ACG CCA CAC GCC TGG TAC TT - #C CAG CAG GCA GGC AAC          1994                                                                           Asp Val Asp Lys Thr Pro His Ala Trp Tyr Ph - #e Gln Gln Ala Gly Asn            #   535                                                                        - GGG ATT TTC GCT CTG CAA GCG TTA CTG GCA CT - #G GTT CTG AAT CGG GCC          2042                                                                           Gly Ile Phe Ala Leu Gln Ala Leu Leu Ala Le - #u Val Leu Asn Arg Ala            540                 5 - #45                 5 - #50                 5 -        #55                                                                            - GCG ACC AGC GAC TGATCGCACA CGCAGGACAG CCCCACAACC GG - #CGCGGCTG              2094                                                                           Ala Thr Ser Asp                                                                - TGTTCAACGA CACACGATGA GTCCCCCACT CGGTCTTGTA CTCGGATCCT TT - #T               2147                                                                           - (2) INFORMATION FOR SEQ ID NO:15:                                            -      (i) SEQUENCE CHARACTERISTICS:                                           #acids    (A) LENGTH: 559 amino                                                          (B) TYPE: amino acid                                                           (D) TOPOLOGY: linear                                                 -     (ii) MOLECULE TYPE: protein                                              -     (xi) SEQUENCE DESCRIPTION: SEQ ID NO:15:                                 - Met Leu Glu Leu Leu Pro Thr Ala Val Glu Gl - #y Val Ser Gln Ala Gln          #                 15                                                           - Ile Thr Gly Arg Pro Glu Trp Ile Trp Leu Al - #a Leu Gly Thr Ala Leu          #             30                                                               - Met Gly Leu Gly Thr Leu Tyr Phe Leu Val Ly - #s Gly Met Gly Val Ser          #         45                                                                   - Asp Pro Asp Ala Lys Lys Phe Tyr Ala Ile Th - #r Thr Leu Val Pro Ala          #     60                                                                       - Ile Ala Phe Thr Met Tyr Leu Ser Met Leu Le - #u Gly Tyr Gly Leu Thr          # 80                                                                           - Met Val Pro Phe Gly Gly Glu Gln Asn Pro Il - #e Tyr Trp Ala Arg Tyr          #                 95                                                           - Ala Asp Trp Leu Phe Thr Thr Pro Leu Leu Le - #u Leu Asp Leu Ala Leu          #           110                                                                - Leu Val Asp Ala Asp Gln Gly Thr Ile Leu Al - #a Leu Val Gly Ala Asp          #       125                                                                    - Gly Ile Met Ile Gly Thr Gly Leu Val Gly Al - #a Leu Thr Lys Val Tyr          #   140                                                                        - Ser Tyr Arg Phe Val Trp Trp Ala Ile Ser Th - #r Ala Ala Met Leu Tyr          145                 1 - #50                 1 - #55                 1 -        #60                                                                            - Ile Leu Tyr Val Leu Phe Phe Gly Phe Thr Se - #r Lys Ala Glu Ser Met          #               175                                                            - Arg Pro Glu Val Ala Ser Thr Phe Lys Val Le - #u Arg Asn Val Thr Val          #           190                                                                - Val Leu Trp Ser Ala Tyr Pro Val Val Trp Le - #u Ile Gly Ser Glu Gly          #       205                                                                    - Ala Gly Ile Val Pro Leu Asn Ile Glu Thr Le - #u Leu Phe Met Val Leu          #   220                                                                        - Asp Val Ser Ala Lys Val Gly Phe Gly Leu Il - #e Leu Leu Arg Ser Arg          225                 2 - #30                 2 - #35                 2 -        #40                                                                            - Ala Ile Phe Gly Glu Ala Glu Ala Pro Ile Gl - #u Gly Arg Gln Lys His          #               255                                                            - Ile Ile Ser Ile Asn Asp Leu Ser Arg Asp As - #p Leu Asn Leu Val Leu          #           270                                                                - Ala Thr Ala Ala Lys Leu Lys Ala Asn Pro Gl - #n Pro Glu Leu Leu Lys          #       285                                                                    - His Lys Val Ile Ala Ser Cys Phe Phe Glu Al - #a Ser Thr Arg Thr Arg          #   300                                                                        - Leu Ser Phe Gln Thr Ser Met His Arg Leu Gl - #y Ala Ser Val Val Gly          305                 3 - #10                 3 - #15                 3 -        #20                                                                            - Phe Ser Asp Ser Ala Asn Thr Ser Leu Gly Ly - #s Lys Gly Glu Thr Leu          #               335                                                            - Ala Asp Thr Ile Ser Val Ile Ser Thr Tyr Va - #l Asp Ala Ile Val Met          #           350                                                                - Arg His Pro Gln Glu Gly Ala Ala Arg Leu Al - #a Thr Glu Phe Ser Gly          #       365                                                                    - Asn Val Pro Val Leu Asn Ala Gly Asp Gly Se - #r Asn Gln His Pro Thr          #   380                                                                        - Gln Thr Leu Leu Asp Leu Phe Thr Ile Gln Gl - #u Thr Gln Gly Arg Leu          385                 3 - #90                 3 - #95                 4 -        #00                                                                            - Asp Asn Leu His Val Ala Met Val Gly Asp Le - #u Lys Tyr Gly Arg Thr          #               415                                                            - Val His Ser Leu Thr Gln Ala Leu Ala Lys Ph - #e Asp Gly Asn Arg Phe          #           430                                                                - Tyr Phe Ile Ala Pro Asp Ala Leu Ala Met Pr - #o Gln Tyr Ile Leu Asp          #       445                                                                    - Met Leu Asp Glu Lys Gly Ile Ala Trp Ser Le - #u His Ser Ser Ile Glu          #   460                                                                        - Glu Val Met Val Glu Val Asp Ile Leu Tyr Me - #t Thr Arg Val Gln Lys          465                 4 - #70                 4 - #75                 4 -        #80                                                                            - Glu Arg Leu Asp Pro Ser Glu Tyr Ala Asn Va - #l Lys Ala Gln Phe Val          #               495                                                            - Leu Arg Ala Ser Asp Leu His Asn Ala Lys Al - #a Asn Met Lys Val Leu          #           510                                                                - His Pro Leu Pro Arg Val Asp Glu Ile Ala Th - #r Asp Val Asp Lys Thr          #       525                                                                    - Pro His Ala Trp Tyr Phe Gln Gln Ala Gly As - #n Gly Ile Phe Ala Leu          #   540                                                                        - Gln Ala Leu Leu Ala Leu Val Leu Asn Arg Al - #a Ala Thr Ser Asp              545                 5 - #50                 5 - #55                            __________________________________________________________________________ 

We claim:
 1. An expression vector useful for the production of a heterologous polypeptide in a halobacterium host cell, said vector comprising:a) an operable halobacterium transcription and translation regulatory DNA sequence; b) a DNA sequence encoding a heterologous polypeptide located 3' to said regulatory DNA sequence of a); and c) operable halobacterium transcription and translation stop signals located 3' to said DNA sequence encoding a heterologous polypeptide of b).
 2. The vector according to claim 1 having a DNA sequence encoding replication and/or selection capability for said halobacterium host cell.
 3. The vector according to claim 1 containing an additional DNA sequence encoding the pre-sequence of bacteriorhodopsin gene between said regulatory DNA sequence of a) and said DNA sequence encoding a heterologous polypeptide of b) for expression of a fusion polypeptide of said pre-sequence with said heterologous polypeptide.
 4. The vector according to claim 1 or 3 containing an additional DNA sequence encoding at least a membranous domain of the bacteriorhodopsin gene and a DNA sequence operably encoding a unique protease cleavage site and a restriction site, in optional order, between said DNA sequence encoding at least a membranous domain and said DNA sequence encoding a heterologous polypeptide of b), said additional DNA sequence located 3' to said DNA sequence encoding a heterologous polypeptide of b).
 5. A halobacterium host cell transformed with a vector according to claim
 1. 6. A halobacterium host cell transformed with a vector according to claim
 4. 7. A method for producing a heterologous polypeptide in a halobacterium host cell, said method comprising:a) transforming a halobacterium host cell with an expression vector, said expression vector comprising:i) an operable halobacterium transcription and translation regulatory DNA sequence; ii) a DNA sequence encoding a heterologous polypeptide located 3' to said regulatory DNA sequence of i); and iii) operable halobacterium transcription and translation stop signals located 3' to said DNA sequence encoding a heterologous polypeptide of ii); and b) causing expression of said DNA sequence encoding a heterologous polypeptide of ii);wherein said heterologous polypeptide is other than a halobacterium polypeptide.
 8. The method according to claim 7 wherein said elements include an additional DNA sequence encoding at least a membranous domain of the bacteriorhodopsin gene and a DNA sequence operably encoding a unique protease cleavage site and a restriction site, in optional order, between said DNA sequence encoding at least a membranous domain and said DNA sequence encoding a heterologous polypeptide of ii), said additional DNA sequence located 3' to said DNA sequence encoding a heterologous polypeptide of ii).
 9. A method for producing a heterologous polypeptide in a halobacterium host comprising causing expression of DNA encoding said heterologous polypeptide wherein an expression vector comprising the DNA encoding said heterologous polypeptide is operably expressed in said halobacterium host and said heterologous polypeptide is other than a halobacterium polypeptide.
 10. A method for producing a heterologous polypeptide in a halobacterium host comprising:a) transforming said halobacterium host with an expression vector encoding a fusion polypeptide, said expression vector comprising:i) halobacterium transcription and translation regulatory DNA; ii) DNA encoding a heterologous polypeptide; iii) DNA encoding a unique protease cleavage site; iv) DNA encoding a membranous domain of bacteriorhodopsin; v) wherein said DNA of i), ii), iii), and iv) is operably linked; b) causing expression of DNA encoding said fusion polypeptide such that said fusion polypeptide is localized in the membranes; and c) incubating cells of said halobacterium host comprising said membrane-bound fusion polypeptide with a protease such that said protease cleaves at said unique protease cleavage site to release said heterologous polypeptide from said membranes;wherein said heterologous polypeptide is other than a halobacterium polypeptide. 